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Paper ID:2

The Effect of Leading-Edge Serration at Owl Wing Feathers on Flow Induced Noise Generation

Suprabha Islam*, Sifat Ullah Tanzil

Energypac Power Generation Ltd., Bangladesh

Abstract:

During past few decades, being amazed by the excellent silent flight of owl, scientists have been trying to demystify the unique features in its wing feathers. Our present study was undertaken for a better understanding of this phenomenon. In this study, a numerical investigation was performed to analyse how the shape of the leading-edge serration at owl wing feathers affects the flow induced noise generation. For the analysis, owl inspired single feather wing models were prepared with and without serrations at the leading edge. The serration profiles were taken at different positions of the vane length for a single wing feather. Broadband noise was studied to quantify the local contribution to the total acoustic power generated by the flow, where the results clearly showed the effect of serrations in reducing the noise generation. It was also clearly visible that the shape of the serration has a very strong influence on noise generation. The frequency spectrum of noise was also analysed and a strong relation was found between the shape of the serration and the noise generation. It showed that, the noise suppression is strongly influenced by the height to length ratio of the serration. With the increase of height to length ratio the noise suppression is enhanced further.

Paper ID:5

Improvement in Aerodynamic Performance of NACA0021 Airfoil Using Moving Surface Boundary Layer: A Computational Study

Md. Abdus Salam*, Vikram Deshpande ,Shoyon Panday ,Nafiz Ahmed Khan ,M. A. Taher Ali Ali

Military Institute of Science & Technology, Bangladesh

Abstract:

The NACA0021 being a thick airfoil, possesses soft stall behavior with moderate maximum coefficient of lift (clmax). The present study focusses to improve aerodynamic performance using the moving surface boundary control. The modifications to airfoil include a rotating leading edge cylinder with airfoil aft body. The leading edge rotating cylinder injects momentum in top surface boundary layer thereby keeping the flow attached in the otherwise adverse pressure gradient. The attached flow over top surface shall contribute to improve the airfoil aerodynamic performance in terms of lift, drag and stall angle. The present computational study focusses on modified airfoil performance for varying velocity ratios (i.e. ratio of tangential velocity of rotating cylinder and free stream velocity) between 0.0 and 1.78 at different airfoil angles of attack. The computational study clearly highlights improvement in modified airfoil aerodynamic performance in terms of coefficient of lift, drag, stall angle and clmax even at velocity ratios less than 1.0. The lift and drag characteristics of modified airfoil are found to be superior to base airfoil for velocity ratios beyond 0.356 and 0.7 respectively. The stall angle of attack for modified airfoil is also seen to increase linearly with velocity ratio. The stall angle of attack nearly doubles from 10 degree for stationary leading edge to 19o for velocity ratio of 1.78. The extent of momentum injection in boundary layer with varying cylinder speed is analysed by comparing the coefficient of pressure plots. The aerodynamic performance improvement thus achieved by momentum injection by low cost and practically feasible leading edge rotating cylinder in NACA 0021 promises its possible utilization for varied applications i.e. for low speed aircraft wing, wind turbine blades and hydrofoils.

Paper ID:9

Thermal Model Development and Performance Analysis of a Biomass Combustor Supported Power Generation and Grain Drying System

AYAN MONDAL, ARITRA GANGULY *

Indian Institute of Engineering Science and Technology, Shibpur

Abstract:

In the present work, a scheme of a biomass combustion based system has been proposed for combined power generation and Fluidized Bed Drying (FBD) of agricultural food-grains. The proposed dryer has been used to dry grains of paddy. An Organic Rankine Cycle (ORC) powered through biomass combustor has been used to generate electrical power. The ORC is coupled with an FBD system by means of a process heater which can supply hot air at the required drying temperature. A thermal model has been developed for the proposed drying cum power generation system. The results obtained by the thermal model have been validated against a reference model study available in literature. The performance of the proposed system in terms of drying time has been analyzed for various months of a calendar year for the climatic condition of Kolkata (22°34ʹN 88°22ʹE), located in the plains of Indian subcontinent. Parametric studies have been conducted to understand the effect of various parameters on the performance of the system. The study shows the viability of development of a biomass powered combined power generation and drying system for developing countries like India.

Paper ID:12

Performance Enhancement Of Solar Hybrid PV/T By Using Glycerin as Additives

SUBIR KUMAR GHOSH *, Monjur Mourshed; M. H. Masud

Rajshahi University of Engineering & Technology, Bangladesh

Abstract:

The application of various forms of renewable energy is increasing day by day with the decreasing trend of fossil fuel reserve across the globe. Solar energy is one of the most affordable and popular renewable energy that is used and implemented around the world at a large scale. The present study illustrates an experimental research work of hybrid PV/T system in northern area of Bangladesh. The efficiency of PV/T system depends on the amount of irradiation and the mass flow rate of the working fluid. Moreover, the heat generated in the solar panel reduces its performance. In this study, a combined approach is used to dissipate the heat and simultaneously produce hot air and water by using the trapped heat energy in the system. This designed system ensures the growth of overall efficiency up to 39.68% and subsequently decrease the energy loss. The experimental work also extended to analyze the effect of glycerin addition at a ratio of 50: 1 (% of wt.) with water that yields the combined efficiency up to 45.76%. Also, a financial analysis shows its feasibility in the developing countries.

Paper ID:14

Thermal Performance Analysis of Plate Fin Arrays with Hexagonal Perforations under Turbulent Flow Regime

Imtiaz Taimoor*; Md Lutfor Rahman , Nazneen Sultana Aankhy , Muzahid Bin Khalid

Military Institute of Science and Technology, Bangladesh

Abstract:

Heat transfer enhancement has been a major concern in modern days in designing heat generating equipment. In the present study an experimental demonstration has been investigated to analyze the thermal performance of solid plate fin arrays and plate fin arrays with hexagonal perforations where the perforations are along the length of the fin, in the turbulent flow regime under steady state forced convection. The air velocity was varied ranging from 4ms-1 to 12ms-1 and data were recorded after a certain period of time at a constant heat flux. The performance of solid plate fin and plate fin with hexagonal perforation as heat sink was tested and best result was found in case of plate fin with hexagonal perforations. Convective heat transfer co-efficient, fin effectiveness, fin efficiency seem to increase in hexagonal perforation than solid ones. Thermal resistance seems to decrease in plate fin with hexagonal perforations than solid fins. This study suggests that most important parameter that govern the performance of fin is the fin geometry and varied cross section i.e. perforations.

Paper ID:30

Analysis of the process parameters of solid particle erosion of copper using taguchi and regression analysis

Uttam Kumar Debnath1; Bengir Ahmed Shuvho 1 ,Mohammad Asaduzzaman Chowdhury1 *,Dewan M Nuruzzaman2

1Dhaka University of Engineering and Technology (DUET), Gazipur, Bangladesh

2University Malaysia Pahang

Abstract:

The erosion characteristics of copper have been evaluated practically at a variety of test parameters using dry compressed air jet test rig under ambient temperature. Random shape silica sand (SiO2) is taken in to account as erodent within range of 300-600 mm. The maximum level of erosion is obtained at impact angle 15° which indicates the ductile manner of the tested copper. The higher the impact velocity to effect on the kinetic energy as a result it is increase the erosion rate. Taguchi design of experimental methodology, Grey relational and regression analysis was applied for optimizing the process parameters in the erosion of the copper. The test results are designated using Taguchi’s concept to ensure the minimization of observations for clarification of results in alternative process. The analysis of variance (ANOVA) was applied to find the significant factors in the process. Nonlinear regression model has been generated with respect to Grey Relational Grade and the factors of the all tested conditions. The confirmation of the test is conducted with the optimal factors levels to validate the proposed approach in this study.

Paper ID:31

A comprehensive Analysis of Natural Convection in a Trapezoidal Cavity With Magnetic Field and Cooled Triangular obstacle of different Orientations

Muhammad Sajjad Hossain *

Ahsanullah University of Science and Technology, Bangladesh

Abstract:

The phenomenon of natural convective flow being there with magnetic field in a trapezoidal cavity with cold triangular obstacle for different leaning angles ф (ф = 00, 300, 450) has been studied in this work numerically. The horizontal wall of the cavity is considered as non-uniformly heated while the upper wall of the cavity is thermal insulated and other side walls are at a cold temperature. Finite element technique of Galerkin weighted residual method (GWRM) is used to solve the principal partial differential equations. The numerical calculations are worked out for magnetic field parameter, such as, Hartmann number, Ha (0≤Ha≤200), which is used to find the effects on flow and temperature field and the study is also executed for other buoyancy parameters Rayleigh number, Ra (103≤Ra≤106) and Prandtl number, Pr = 0.7 and also for diverse orientations or rotations (00≤rot≤900) of cold triangular obstacle of the cavity. The obtained results are demonstrated in terms of streamlines, isotherms, heat transfer rates as well as local and average Nusselt numbers affected by the rotations of cold triangular obstacle and also aforesaid parameters. Keywords: Natural convection, Magnetic Field, GWRM, Trapezoidal cavity, Cooled triangular obstacle, Non-Uniform heating

Paper ID:35

A Simplified One-Equation Elliptic-Relaxation Model

Md Mizanur Rahman *

Aalto University

Abstract:

A simplified version of a one-equation R=C_\mu k^2/\epsilon turbulence model with elliptic relaxation, formulated by Elkhoury \cite{Me} containing explicitly constant coefficients, is proposed that accounts for the distinct effects of low-Reynolds number (LRN) and near-wall turbulence. In the simplified model, coefficients and functions are constructed such as to preserve the anisotropic characteristics of turbulence encountered in nonequilibrium flows. The constant-dependent sensitivity of characteristic length scale associated with the elliptic relaxation function is reduced to an extent. Unlike the Elkhoury model, it requires the elliptic equation for the elliptic relaxation parameter $f_R$ with a source term 1.0 (one) to be solved in conjunction with the $R$-equation model. A near-wall damping function is introduced to relax the viscous length-scale coefficient of the elliptic relaxation model. This incentive approach stems from the combination of wall-viscous (LRN) and wall-blocking (nonlocal) effects. The simplified model is validated against a few well-documented flow cases, yielding predictions in good agreement with the direct numerical simulation (DNS) and experimental data. Comparisons indicate that the new model improves the accuracy of flow simulations compared to the widely used Spalart-Allmaras model and remains competitive with the original Elkhoury and SST k-omega models.

Paper ID:37

Numerical Study on Aerodynamic Drag by Variation of Rear Side Slope of Sedan Cars

Masnun Mehedi *; Zisan Mahmud , Md. Ali

Bangladesh University of engineering and Technology, Bangladesh

Abstract:

Aerodynamic drag is the force that acts on a body moving through air opposite to the direction of motion of the body. Drag force affects the performance of aircraft, road bikes or cars as it works opposite to the direction of movement. About 50 to 60 percent of total fuel energy is lost only to overcome this force. The drag reduction of cars is a major topic in the automotive industry because of its close link with fuel consumption reduction. One of the main causes of aerodynamic drag for sedan cars is the separation of flow near the rear end of the vehicles. The objective of this research is to study the flow behavior around sedan cars with a particular type of rear shape. In this research, computational fluid dynamics (CFD) technique is used. This research focuses on investigating the effects of rear side design modification of sedan cars to reduce flow separation. This paper presents the optimization result, the effect of rear shape modification in the flow field like, the increase in rear side slope angle decreases drag and how these effects take place

Paper ID:38

Numerical Analysis of the Effect of Different Orientations of Rectangular Inserts to Enhance Heat Transfer in a Circular Tube

Mostofa Kamal *; Ujjwal Kumar Deb , Md. Omar Faruk

Chittagong University of Engineering & Technology, Bangladesh

Abstract:

In this paper, we have numerically investigated the effect of different orientations of rectangular inserts in a laminar regime (1600

Paper ID:39

Numerical study of MHD mixed convection heat transfer of nanofluid in a lid-driven porous rectangular cavity with three square heating blocks

Md Humaun Kabir *

Jashore cantonment college, Jashore, Bangladesh

Abstract:

Abstract The present numerical study explores the MHD mixed convection heat transfer of nanofluid in a lid-driven porous rectangular cavity with three square heating blocks. Two- dimensional Navier-Stokes and energy equation are solved using the finite element method. The top and bottom walls of the enclosure are maintained at temperature Tc. The left and right walls are kept adiabatic. Three square heating block inside the enclosure. To investigate the effect of Hartmann number, Darcy number and Richardson number on the fluid flow and heat transfer characteristics inside the enclosure. A set of graphical results are presented in terms of streamlines, isotherms, dimensionless temperature, velocity profiles and average Nusselt numbers. The results reveal that heat transfer rate increases as increasing Darcy number and Richardson number. It is observed that, Hartmann number is a good control parameter for heat transfer in fluid flow through porous medium in enclosure. Moreover, Cu-water nanofluid has greater merit to be used for heat transfer enhancement. The method used is validated against previous works.

Key words: Mixed convection, Magnetic field, Square enclosure, Porous medium, Nanofluid flow

Paper ID:41

Evaluation and Calibration of an Inertial Measurement Unit

Hafiz Ahamed 1*; Md. Riaz Pervez1, Md Manirul Islam1, Dipl.-Ing. Christof Hille 2 ,Hubert Roth 2

1Rajshahi University of Engineering & Technology, Bangladesh

2University of Siegen

Abstract:

The Micro-electro-mechanical systems (MEMS) have been adopted into various applications such as navigation or positioning, consumer electronics, medical electronics. It provides low fabrication cost, lightweight and low-power chip-based accelerometers and gyroscopes. The signals for inertial measurement unit (IMU) is greatly depends on the sensor’s proper installment. Due to this fact, these low-cost sensors are in great need of a calibration procedure. This paper presents evaluation and calibration of an inertial measurement unit, Ultra-Miniature 6 (UM-6). An experimental setup has been developed for this purpose. The UM6 sensor was placed on the setup and the sensor frame rotating around the standard coordinate system. An electrical circuit was designed to connect the sensor with personal computer. An UART serial protocol was used for communication. Data acquisition system based on Visual C++ was used for archiving of the measurement data, whereas further data processing was performed in Microsoft Excel. This raw experimental data was placed on a mathematical equation for developing calibration data and compare it with sensor provided calibration data for evaluation. The algorithm is shown to give good results using data from the IMU units. The experimental error was 10%, 16.67% and 18.18% consecutively x, y and z gyro coordinate and satisfactory results were also shown for accelerometer. Hence the experimental results demonstrate the effectiveness of the proposed method of calibration.

Paper ID:42

Nano Fluid Flow Along the Riga Plate with Electromagnetic Field in a Rotating System

Orientations

Md Alam Mahmud*

Khulna University, Bangladesh

Abstract:

Nano-fluid flow with the influence of magnetic field along the Riga plate in a rotating system has been investigated numerically. By using usual transformation, the systems of governing nonlinear coupled partial differential equations are transformed into a dimensionless nonlinear coupled partial differential equations. The obtained dimensionless nonlinear partial differential equations have been solved by explicit as well as implicit finite difference method. The stability analysis has been established and convergence criteria has also been analyzed. The Compaq visual FORTRAN 6.6a and MATLAB R2015a have been used as tools to simulate the above mentioned dimensionless nonlinear partial differential equations. The obtained results have been shown graphically as well tabular form. Also the validity, comparison, accuracy and convergence have been shown graphically as well as mathematically.

Paper ID:43

Fluid Flow Through a Straight Pipe in a Rotating System with Magnetic Field Acting Along Center Line having Hall Current

Md Alam Mahmud *; Kaniz Fatima Limaa

Khulna University, Bangladesh

Abstract:

Fluid flow through a straight pipe in a rotating system with magnetic field acting along center line having hall current is investigated numerically. A cylindrical co-ordinate system has been employed to derived the steady two dimensional momentum equations. By using usual transformation, the steady two dimensional coupled nonlinear partial momentum equations are transferred into non-dimensional coupled nonlinear partial momentum equations. To solve this equations, the Spectral Method has been used as a main tool and the Collocation Method, Chybyshev Polynomial and Newton-Raphson Method are also used as the secondary tools. Also, Arc length Method is used to compute the critical zone results. The influence of magnetic parameter, hall parameter, pressure gradient parameter and rotating parameter, the nature of the total flow(flux) and stream line flow are investigated with different aspect ratios. For strong hall current, magnetic force and Coriolis force, all fluid particles strength are weak. The Compaq visual FORTRAN 6.6a, Tech plot and Gost Script as well as Gost View software’s are used for simulation as well as plotting. Finally the axial flow and stream line flow have been shown in contour and stream line format.

Paper ID:47

Hall Effects on Casson Fluid Flow along a Vertical Plate

Mohammad Rafiqul Islam *; Mst Sonia Akter

Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Bangladesh

Abstract:

The Hall effects on Casson fluid flow along a vertical plate has been investigated numerically. The governing equations have been derived from Navier-Stokes’ equation and boundary layer approximation has been employed. By using usual transformations, the obtained non-linear coupled partial differential equations have been transformed into dimensionless governing equations. These equations have been solved by applying the explicit finite difference method. The MATLAB R2015a tool has been used for numerical simulation. The stability and convergence criteria have been analyzed. The effect of some important parameters on the primary velocity, secondary velocity, temperature and concentration distributions as well as local shear stress, Nusselt number and Sherwood number have been shown graphically.

Paper ID:52

Fluid Flow along the Riga Plate with the Influence of Magnetic Force in a Rotating System

Sheela Khatun1 , Muhammad Minarul Islam1 *, Md. Tusher Mollah, Md Alam Mahmud2

1Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Bangladesh

2Khulna University , Bangladesh

Abstract:

The fluid flow along the Riga plate with the influence of magnetic force in a rotating system has been investigated numerically. The governing equations have been derived from Navier-Stokes’ equations. Applying the boundary layer approximation, the appropriate boundary layer equations have been obtained. By using a usual transformation, the obtained governing equations have been transformed into a coupled dimensionless non-linear partial differential equation. The obtained dimensionless equations have been solved numerically by an explicit finite difference scheme. The simulated results have been obtained by using MATLAB R2015a. Also, the stability and convergence criteria have been analyzed. The effect of several parameters on the primary velocity, secondary velocity, temperature distributions as well as the local shear stress and the Nusselt number have been shown graphically.

Paper ID:55

Numerical simulation of mixed convection heat transfer of nanofluid in a lid-driven porous medium square enclosure

Mohammod Jahirul Haque Munshi *.

Hamdard University Bangladesh

Abstract:

This present numerical simulation of mixed convection heat transfer of nanofluid in a lid-driven porous medium square enclosure with several pairs of heat source- sinks. Two- dimensional Navier-Stokes, energy equations are solved using the finite element method. The top and bottom walls of the enclosure are maintained at temperature Tc. The left and right walls are kept adiabatic. Two square heating and cold blocks inside the enclosure. To investigate the effect of Hartmann number, Darcy number and Richardson number on the fluid flow and heat transfer characteristics inside the enclosure. A set of graphical results are presented in terms of streamlines, isotherms, dimensionless temperature, velocity profiles and average Nusselt numbers. The results reveal that heat transfer rate increases as increasing Darcy number and Richardson number. It is observed that, Hartmann number is a good control parameter for heat transfer in fluid flow through porous medium in enclosure. Moreover, Cu-water nanofluid has greater merit to be used for heat transfer enhancement. The method used is validated against previous works.

Paper ID:57

Numerical Prediction of Froth Layer Height in Slurry Column

Abd Alhamid Rafea Sarhan1 , Md. Abdul Karim Miah2 *, Jamal Naser1

1. Swinburne University of Technology

2. Islamic University of Technology (IUT) , Bangladesh

Abstract:

Flotation is a widely used separation method within the minerals processing industry, as well as being used for water treatment and de-inking of recycled paper. The froth layer and its role in the separation achieved in flotation cell have been studied. A Computational Fluid Dynamics (CFD) model was developed and validated against published experimental data. The model was built by writing FORTRAN subroutine and incorporating then into the commercial CFD code AVL FIRE, v.2014. The effect of coalescence process due to ﬁlm rupture was considered in the froth phase. Then the model was used to predict the height of froth layer. Keywords: CFD, froth, gas holdup, solid concentration, superficial gas velocity.

Paper ID:58

Hydrodynamic Instability with Convective Heat Transfer through a Curved Channel with Strong Rotational Speed

Mohammad Sanjeed Hasan1 * Rabindra Nath Mondal2 , Toshinori Kouchi3 , Shinichiro Yanase3

1Bangabandhu Sheikh Mujibur Rahman Science & Technology University, Gopalganj-8100, Bangladesh.

2Jagannath University, Dhaka, Bangladesh

3Faculty of Engineering, Okayama University, Okayama 700-8530, Japan

Abstract:

In this paper, a comprehensive numerical study on viscous incompressible fluid flow and heat transfer through a loosely coiled square duct has been presented. Spectral method is used as a basic tool to solve the system of partial differential equations. Numerical calculations are carried out for the Dean number, Dn = 1000, applying a temperature difference across the vertical sidewalls for the Grashof number Gr = 100, where the outer wall is heated and the inner wall cooled. A rotation of the duct about the center of curvature is imposed in the positive direction for the Taylor number and combined effects of the centrifugal, Coriolis and buoyancy forces are investigated. First, steady solutions are obtained by the Newton-Raphson iteration method. As a result, three branches of asymmetric steady solutions with two- to four-vortex solutions are obtained. Then, time evolution calculations as well as power spectrum of the unsteady solutions are obtained and it is found that the unsteady flow undergoes through various flow instabilities, if Tr is increased in the positive direction. Nusselt numbers are calculated as an index of convective heat transfer, and it is found that convective heat transfer is significantly enhanced by the secondary flow. Finally, a comparison between the numerical and experimental investigations has been provided, and it is found that there is a good agreement between the numerical and experimental investigations.

Paper ID:59

Bifurcation Structure and Unsteady Solutions through a Curved Square Duct with Bottom Wall Heating and Cooling from the Ceiling

Mohammad Sanjeed Hasan1 *, Muhammad Minarul Islam1 , Samir Chandra Ray1 , Rabindra Nath Mondal2

1Bangabandhu Sheikh Mujibur Rahman Science & Technology University, Gopalganj-8100, Bangladesh.

2Jagannath University, Dhaka, Bangladesh

Abstract:

The present paper investigates a spectral-based numerical study for the fully developed two-dimensional flow of viscous incompressible fluid through a curved square duct for the constant curvature . The bottom wall of the duct is heated while cooling from the ceiling; the inner and outer sidewalls being thermally insulated. Flow characteristics are investigated over a wide range of the Dean number for the Grashof number Gr = 100. First, we investigated solution structure of the steady solutions by using Newton-Raphson iteration method. As a result, four branches of steady solutions are obtained with a bifurcating relationship among the branches. Then, we studied unsteady solutions by time evolution calculations justified by their phase spaces, and it is found that the unsteady flow undergoes in the scenario “steady-state periodic (multi-periodic) chaotic”, if Dn is increased. The present study demonstrates the role of secondary vortices on convective heat transfer and it is found that convective heat transfer is significantly enhanced by the secondary flow; and the chaotic flow, which occurs at large Dn’s, enhances heat transfer more effectively than the steady-state or periodic solutions.

Paper ID:61

Thermal modeling and performance analysis of a solar assisted double-effect vapor absorption system based cold storage

ARITRA GANGULY1 *, Ramen Kanti De2

1Indian Institute of Engineering Science and Technology, Shibpur

2OmDayal Group of Institutions, Uluberia, Howrah 711316

Abstract:

The demand of cold storage technology for food preservation has increased enormously in the past few decades.The vapor compression based cold storages are very common at present. However, the rising cost of fossil fuels and considerable environmental pollution caused by the refrigeration devices, encouraging the utilization of vapor absorption technology. In this work, an attempt has been made to propose a 20 TR cold storage based on double-effect, series flow vapor absorption cycle to store a variety of high value perishable commodities round the year. To meet the year round heat and electrical load of the proposed cold storage, a solar PV-thermal based hybrid power system has been proposed. A computer program in MATLAB-R2017a has been developed to predict the year round performance of the proposed system. The performance of the cold storage has been analyzed for a complete calendar year considering the climatic condition of Kolkata, India (22.57⁰ N, 88.36⁰ E). The study reinforces the need and viability of double effect VAR system based cold storage powered through solar energy in the developing countries of the world. Keywords: Double effect, Absorption; cold storage; photovoltaic; parabolic trough; collectors.

Paper ID:62

MHD Free Convection Maxwell Nanofluid Flow through an Exponentially Accelerated Vertical Surface in the Presence of Radiation

Rajib Biswas1 *, Mehedy Hasan2, B.M. Jewel Rana1 , Sarder Firoz Ahmmed1

1Khulna University, Khulna, Bangladesh

2Bangladesh University of Engineering and Technology, Bangladesh

Abstract:

The unsteady MHD free convection Maxwell nanofluid flow through an exponentially accelerated vertical surface with the presence of radiation and chemical reaction is investigated. For obtaining numerical solutions, the governing partial differential equations (PDEs) are transformed into dimensional partial differential equations (PDEs) with the usual transformations. Explicit finite difference method (EFDM) have been used for numerical solutions where ForTran programing language have been used as the main tool of investigations. The stability analysis technique (SAT) is used for choosing the appropriate values of parameters. Then, the obtained numerical results are affected by this various dimensionless parameters such as magnetic parameter (M), Maxwell parameter (Mx), Schmidt number (Sc), Grashof number (Gr), Lewis number (Le) and so on. The velocity, temperature and concentration profiles along with the skin friction coefficient (Cf), Nusselt number (Nu) and Sherwood number (Sh) are analysed for different perspective. Furthermore, the streamlines and isotherms have been discussed for different interesting parameters in this work. Finally, the results are discussed after stability convergence test (SCT) by using graphics software tecplot-9 and comparison of our results with the previous results have been presented in a tabular form.

Paper ID:78

Biomagnetic Fluid Flow Past a Stretching/Shrinking Sheet With Slip conditions Using Lie Group Analysis

Ghulam Murtaza1 *, E. E Tzirtzilakis2 , Ferdows Mohammad3

1Comilla University, Bangladesh

2Department of Mechanical Engineering Technological Educational Institute of Western Greece, 1 M. Aleksandrou Str, Koukouli, 26334 Patras, Greece.

3Unievrsity of Dhaka, Bangladesh

Abstract:

The purpose of this paper is to investigate the boundary layer flow and heat transfer of biomagnetic fluid over a stretching/shrinking sheet in the presence of magnetic dipole. We use Lie group transformation to develop similarity transformation. Using this special form of transformation namely Lie group transformation, the governing nonlinear partial differential equations are reduced into a system of couple nonlinear ordinary differential equations subject to associated boundary conditions. The reduced resulting equation are then solved numerically by using MATLAB routine boundary value problem solver bvp4c. The effects of the pertinent parameters such as ferromagnetic parameter, suction parameter, stretching parameter and momentum slip parameter on the flow field and temperature as well as skin friction coefficient and heat transfer rate are presented and discussed through graphically in this study. Results indicate that the dual solutions exits for some specific range of governing parameter. The results of the present study have been compared with those reported by previous results and found a very good agreement that supports the validity of the present analysis and the accuracy of our numerical computations.

Paper ID:79

Real time position control of industrial robot over Ethernet based communication framework

Md. Riaz Pervez1, Priyo Nath Roy1 ,Hafiz Ahamed1 *; Calogero Oddo (Nil); Gastone Ciuti2, Paolo Dario2

1Rajshahi University of Engineering & Technology, Bangladesh

2Scuola Superiore Sant'Anna

Abstract:

Industrial robots are often used in positioning and material handling purposes. Due to low accuracy and high stiffness, the researchers are more concern on to improve in control operations like high accuracy trajectory tracking. Owing to the problems, large numbers of sophisticated control algorithms have been developed. This paper presents a real time feed-forward position control of 6 DOF Mitsubishi robot which deals with cartesian parameters monitoring and controlling in real time by the user. The robot movement was operated from remote computer. The Virtual Instrument (VI) was created using LabVIEW software which creates Graphical Control and Monitoring System. An Ethernet User Datagram Protocol (UDP) is used for developing an online transmission process between client and server. This helps in easy and fast transmission of data in form of messages between the client PC(s) and server robot. With the help of this Ethernet protocol, client provides the value of set point according to which the control actions are taken by the server. Finally, experimental validation is performed using a Mitsubishi robot to verify the correctness and accuracy of the approach.

Paper ID:80

Exergy analysis of a novel solar regenerated liquid desiccant assisted evaporative cooling system

ARITRA GANGULY1 *; Avik Ghosh1 ,Jishnu Bhattacharya2

1Indian Institute of Engineering Science and Technology, Shibpur

2IIT Kanpur, India

Abstract:

In this paper, exergy analysis of a novel solar powered liquid desiccant assisted air conditioning system is presented and simulated. The system aims to provide suitable thermal comfort conditions inside office buildings with high internal loads situated in the hot and humid tropical/subtropical countries of the world. The various components of the cooling system are counter flow packed bed dehumidifier, forced parallel flow solar regenerator, dew point indirect evaporative cooler, cooling tower, desiccant-desiccant heat exchanger, desiccant-water heat exchanger and air-water heat exchanger. An aqueous solution of calcium chloride is used as desiccant. Previous research on solar powered liquid desiccant cooling systems has mainly focused on energy analysis, with studies on exergy analysis being limited. Out of the few studies that have focused on exergy analysis, such a novel configuration with the use of direct solar regenerators and dew point indirect evaporative cooler has not been reported before. Direct solar regenerators have higher effectiveness as compared to other regenerator configurations and are more compact having lesser system components. Dew point indirect evaporative coolers are more attractive than traditional direct/indirect evaporative coolers as it can cool the air below the wet bulb temperature without adding moisture to it. The primary objective of this study is to present the exergy destruction in the various system components, along with the overall exergy efficiency of the proposed system. Parametric analyses have been carried out to present the effect of various operating and design parameters on the exergy efficiency of individual components and the system as a whole. This study identifies the sites in the system having maximum exergy destruction with maximum irreversibility and thus paves the way for further system performance enhancement.

Paper ID:81

Effects of Hall and ion-slip currents on MHD Micropolar fluid flow along a vertical plate in a rotating system

Md Delowar Hossain1 *, Abdus Samd2 , Mohammad Ali1 , Md Alam Mahmud3

1Chittagong University of Engineering & Technology

2University of Dhaka, Bangladesh

3Khulna University, Bangladesh

Abstract:

The Effects of Hall and Ion-slip currents on MHD Micropolar fluid flow with free convection along a vertical porous plate in a rotating system have been studied numerically. By using usual transformation, the governing nonlinear coupled partial equations have been transferred into non-dimensional nonlinear coupled partial equations. The dimensionless momentum, angular momentum and energy equations are solved numerically. The obtained equations have been solved numerically by the explicit finite difference method under the stability and convergence analysis. The effects of some important parameters on shear stress, Nusselt number as well as Primary Velocity, Secondary Velocity and Temperature distributions have been discussed graphically by Studio Developer FORTRAN 6.6a. Finally, qualitative and quantitative comparisons of the present study with published results have been discussed.

Paper ID:84

Numerical Study of Magnetohydrodynamic Mixed Convection in a Partially Heated Rectangular Enclosure with Elliptic Block

Md Imran Hossain1 *, M. A. Maleque1, Mohammad Mokaddes Ali2

1Bangladesh University of Engineering and Technology, Dhaka, Bangladesh

2Mawlana Bhashani Science and Technology University Tangail-1902, Bangladesh

Abstract:

Magnetohydrodynamic mixed convection fluid flow and heat transfer in a partially heated rectangular enclosure with elliptic block has been investigated numerically in this study. The left vertical wall is maintained at a high temperature Th and the right vertical wall is supposed to be at low temperature Tc while the remaining horizontal walls are kept adiabatic. The governing differential equations are solved by finite element method (FEM). A uniform magnetic field of strength B0 is applied parallel to the x-axis. Numerical results have been obtained for a wide range of dimensionless parameters such as Richardson number, Hartman number and Reynolds number and presented graphically in the form of streamlines, isotherms contours, average temperature and average Nusselt number along the heated section of the left wall. The obtained result shows that temperature distribution and flow pattern inside the enclosure depended on both strength of the magnetic field and Richardson number and also the presence of elliptic obstacle. In addition, heat transfer rate and average temperature influenced noticiably with the variation of governing parameters.

Paper ID:89

Numerical study of the variable viscosity effect on unsteady pulsatile Ag-water nanofluid flow through a Couette channel of stretching wall with convective heat transfer

M Enamul Karim *

University of Dhaka, Bangladesh

Abstract:

The desire of the current article is to discover the pulse driven Couette flow of Ag-water based nanofluid restrained between two parallel plates with convective heat exchange with the ambient surrounding at the upper wall beneath the combined effects of thermophoresis, Brownian motion and temperature dependent viscosity. The Buongiorno model is considered to illustrate the current flow analysis effectively. In this analysis, the physical properties of water as the base fluid and silver (Ag) as nanoparticles are exercised. The governing flow equations are generalized with the help of boundary layer approximations. Momentum, energy, and nanoparticle concentration equations are generated numerically using finite difference method. The findings of non-dimensional parameters like Brownian motion parameter, Biot number, viscosity variation parameter, stretching velocity parameter, steady pressure gradient, phase angle, and amplitude are conferred graphically. As a final point, skin friction and Nusselt number are anticipated in numeric form with an excellent agreement. From the achieved outcomes, it is noticed that the velocity is directly proportional to the pulsatile pressure gradient.

Paper ID:92

Hydromagnetic mixed convection heat transfer in a tubular enclosure filled with nanofluid

Suprabha Mohammad Mokaddes Ali1 *, M. A. Alim2, Rowsanara Akhter3 , M. A. Maleque2

1Mawlana Bhashani Science and Technology University Tangail-1902, Bangladesh

2 University of Engineering and Technology (BUET), Dhaka-1000, Bangladesh

3International University of Scholars, Dhaka-1212, Bangladesh

Abstract:

The flow and heat transfer characteristics for mixed convection in a tubular enclosure filled withCuO-water nanofluid in presence of external magnetic field is numerically investigated in the present study. The bottom curved wall of the enclosure is taken as isothermally hot and the top curved wall is taken as isothermally cooled while the rest walls are kept adiabatic. The governing partial differential equations are formulated according to the Navier-Stoke equations and energy equation with the help of Boussinesq assumptions. The non-dimensional governing equations are solved numerically with Galerkin weighted finite element method. A detailed parametric discussion is presented for the physical properties of flow and temperature distributions in terms of streamlines, isotherms, average heat transfer rate and average velocity within the flow domain. The results show that the flow and temperature fields are susceptible with the effects of pertinent parameters. Moreover, the heat transfer rate is augmented with increase in Richardson number and concentration of nanoparticles and decrease with greater effects of Hartmann number. Comparison is performed against the previously published results on the basis of special cases and found to be in excellent agreement.

Paper ID:100

Periodic magnetohydrodynamic simulation of Newtonian and non-Newtonian fluids flow behavior past a stretching sheet with nanoparticles

Sk. Reza E Rabbi1 *; S.M. Arifuzzaman2 , Tanmoy Sarkar1 ,M.S. Khan3 , Sarder Firoz Ahmmed1


2School of Computing, Engineering and Mathematics, Western Sydney University

3University of Newcastle

Abstract:

The purpose of this work is to analyze the boundary layer phenomena of Newtonian and non-Newtonian (Casson fluid) nanofluid flow resulting from a stretching sheet with the appearance of periodic magnetic field. Chemical reaction of non-linear order is also considered. The time subservient governing equations such that momentum, thermal and diffusion balance equations are transformed into a convenient dimensionless form by employing finite difference technique explicitly with the support of a programming code namely Fortran 6.6.a. However, a stability and convergence test is also performed for the accurateness of the above mentioned numerical technique and the existing work is found converged for Prandtl number, Pr ≥ 0.048 and Lewis number, Le ≥ 0.016. Furthermore, the impact of diversified physical parameters on momentum, concentric and thermal boundary layers along with skin friction and heat transfer coefficient profiles are presented graphically and also discussed through tabular analysis. Finally, for the validation of the existing work, the current results are compared with the published results and a favorable agreement is attained.

Paper ID:108

Renewable Energy Application in Bangladesh: A Computational Study on Building’s Roof Shapes to Utilize Wind Energy

Ishtier Rahman , Sajid Nakvee *;,Rahul D. Nath , Md. Touhidur Rahman

Military Institute of Science and Technology, Bangladesh

Abstract:

Mounting wind turbines on roof-tops of commercial and residential buildings can be a very promising source of power generation. This study emphasizes on three different designs of roof-tops (viewed from top) to find out a suitable shape in order to utilize a particular design as an accelerator of the general wind flow. A computational study was carried out among these shapes namely half circular, straight convergent and curved convergent. The CFD tool ANSYS Fluent was used to analyze the velocity profiles at different locations of the roof-tops. In addition, suitable locations to mount the turbines were also part of the study. Case study shows that Chittagong, Comilla and some certain places in Dhaka have the minimal wind speed to initiate the turbine to generate energy. A newly designed micro wind-turbine has been proposed as an outcome of this study with a view to harness the wind speed efficiently in the perspective of Bangladesh.

Paper ID:121

Experimental Investigation of Single Basin Solar Still Using Phase Change Material (PCM) as an Energy Storage Medium

Rajib Karmakar *

Rajshahi University of Engineering & Technology, Bangladesh

Abstract:

Solar distillation is one of the significant methods of getting fresh water from brackish and sea water by using free energy source from the sun. This is considered as the best solution for water production in remote, barren to semi-barren, small communities where fresh water is inaccessible. An experimental investigation is performed on a single slope solar still in the weather of Rajshahi, Bangladesh. The main purpose of this study is to evaluate the effect of phase change material (PCM) in a solar still and thus enhance its productivity. A single slope solar still with a basin area of 0.44105m^2 is designed and constructed for this investigation. In this study,Bitumen has been used as phase change material to store thermal energy in the form of latent heat which offersgreat storage capacity per unit volume and per unit mass and provides heat during sunshine-off period. Results show that the efficiency of current solar still with PCM is comparatively higher than that of the still without PCM

Paper ID:125

DESIGN AND MULTIVARIABLE CONSTRAINED OPTIMIZATION OF SHELL AND TUBE HEAT EXCHANGERS

Arnab Mustafi Arka *, Rafsun Hossain Mridha ,Reaz shafqat , Syed Angkan Haider , Faisal Himel , AKM Monjur Morshed

Bangladesh University of Engineering and Technology, Bangladesh

Abstract:

Shell and tube heat exchanger (STHX) is one of the most widely used heat exchangers in industrial applications. The scope of this work was to design and optimize a shell and tube heat exchanger to meet the requirements of effectiveness and cost which are two important parameters in heat exchanger design. For this purpose; thermal design is conducted in which tube inner and outer diameter, length of tube, pitch ratio, tube count ,number of tube pass, clearance, length of shell, shell diameter, baffle thickness were considered as design parameters keeping in mind the restraints of pressure drop and mass flow rates on both the shell-side and the tube-side. For the optimization of shell and tube heat exchanger, it was first thermally modeled using Ɛ-NTU method while Kern method was used to estimate its shell side heat transfer coefficient and pressure drop. After the different fundamental dimensions were obtained from the thermal design, a detailed mechanical design of the heat exchanger was achieved using TEMA specification. A model of a STHX is designed using the commercial software SOLID WORKS. Finally, non-dominated sorting genetic algorithm (NSGA-II) was applied to attain the maximum effectiveness (heat recovery) and the minimum total cost using PYTHON IDE which were considered as two objective functions for optimization. As a result, a set of multiple optimum solutions was gained called ‘Pareto optimal solutions’ which are reported in this paper. Finally a case study is explored by using the optimized design. It was found that optimized cost was $18140 with effectiveness 0.7. The responsiveness analysis of change in optimum effectiveness and total cost with respect to the change in design input parameters was also performed and the range of performance parameters are reported. Keywords: Shell and tube heat exchanger, Multi variable optimization, cost and effectiveness, non-dominated sorting genetic algorithm.

Paper ID:128

A CFD INVESTIGATION OF CONVENTIONAL BRICK KILNS

Faria Tasnim *, Farhan Istiaque, Mohsan Uddin Ahmad, AKM Monjur Morshed


Abstract:

Brick is the most important building material and a largesource of environmental pollution. Most of the kilns used to produce the brick in Bangladesh is backdated and energy inefficient. These poorly performed brick kilns lead to high Green House Gas (GHG) emission and sub-standard brick quality. The objective of this paper is to analyze the brickmaking sectors of Bangladesh and to come up with a concrete recommendations for an energy efficient and environment friendly brick kiln. To evaluate the performance of these conventional kilns, Computational Fluid Dynamics (CFD) simulation approach is applied. CFD analysis helps to simulate the temperature profile of the brick kilns, the mass flow fractions of CO2 and NOxemissions at the outlet, and also the air velocity profile inside the kiln. Turbulence, Combustion and Radiation models are adopted to establish a realistic tunnel kiln environment using ANSYS FLUENT. Using this software detailed analysis of tunnel kiln is done and a comparative analysis between FCK and Zigzag kiln is also presented in this paper.

Paper ID:130

Computational modelling of chemically reactive and radiative flow of Casson-Carreau nanofluids over an inclined cylindrical surface with bended Lorentz force presence in porous medium

Tanmoy Sarker1 *, S.M. Arifuzzaman2 , Sk. Reza E Rabbi1, M.S. Khan3 , Sarder Firoz Ahmmed 1


2School of Computing, Engineering and Mathematics, Western Sydney University

3Department of Chemical Engineering, University of Newcastle

Abstract:

The main objective of this study is to investigate magnetohydrodynamics (MHD) boundary layer heat and mass transfer analysis for Casson-Carrreau nanofluids flowing over an inclined cylindrical surface with bended Lorentz force presence in porous medium. The effects of thermal radiation, higher order chemical reaction, heat generation, Soret and Dufour effects are also considered in multiphase flows. The established partial differential governing equations are transformed into dimensionless momentum, energy and concentric equations and are solved numerically by using explicit finite difference method (EFDM) with employing Compact visual FORTRAN 6.6a programming algorithm. In order to test the accuracy of the system, the stability and convergence analysis are carried out by applying the initial and boundary conditions. A tabular comparison is also shown to validate the numerical modelling and an excellent agreement is examined. The obtained results is discussed for several values of physical parameters viz. Prandtl number, magnetic parameter, Casson fluid parameter, Weissenberg number, thermal Grashof number, mass Grashof number, Biot number, phage angle parameter, Darcy number, heat source parameter, chemical reaction, order of chemical reaction, radiation, Soret and Dufour number, Eckert number, Lewis number, Brownian motion and thermophoresis number on the velocity, temperature, concentration, skin friction, Nusselt number. Finally, it is concluded that the heat and mass transform accomplishment of Casson fluid is relatively lower than that of Carreau fluid.

Paper ID:135

Numerical Aero-thermal-structural analyses of a Fighter Jet Wing during Supersonic Flights

Saiaf Bin Rayhan1 *, Mohsin Islam2

1Nanchang Hangkong University (Graduated) , Nanchang , China -330063

2Islamic University of Technology, Bangladesh

Abstract:

Current research paper deals with numerical analysis of an idealized fighter jet wing in a multi-module aero-thermal-structural environment during supersonic flights. At high Mach number, heat is generated due to the friction between body and the fluid flow, which must be considered for structural analyses. Six different Mach numbers ranging from 1.25 to 2.5 are chosen to understand the effect of viscous heating on the wing model. Ansys CFD is coupled with thermal/structural module to calculate the numerical results. It is observed that for Mach number 1.75 and beyond, equivalent Von-mises stress due to pressure load is almost identical. However, with viscous heating consideration, equivalent stress values increases with higher Mach number which magnifies the significance of thermal loading on the structure.

Paper ID:137

Non-Newtonian Casson fluid flow in presence of magnetic field past an inclined stretching surface in a porous medium with chemical reaction

Md Maruf Hasan (Maruf)*

Abstract:

An analysis of steady two-dimensional non-Newtonian Casson fluid flow past an inclined stretching surface in a porous medium with chemical reaction in presence of magnetic field is considered. The governing partial differential equations are reduced to a system of non-linear coupled differential equations by similarity transformations and are solved them numerically by well-validated Nachtsheim-Swigert shooting method. The influences of various physical parameters on velocity, temperature and concentration profiles are discussed and illustrated graphically. The obtained values for Skin friction coefficient, local Nusselt number and Sherwood number which are of physical and engineering interest are tabulated and found to be in good agreement with previously published results. This study reveals that the concentration profile decreases rapidly with increasing values of chemical reaction parameter.

Paper ID:141

Undisturbed Ground Temperature in Melbourne

Sheikh Khaleduzzaman Shah *, Lu Aye, Behzad Rismanchi

The University of Melbourne

Abstract:

The ground surface temperature changes with the diurnal cycle of solar radiation and ambient air temperature. However, the amplitude of the ground temperature variation diminishes with the increase of the depth of the ground and after a certain depth of the ground, it becomes almost constant, where is termed “undisturbed ground temperature (UGT)”. At this depth, the seasonal changes of solar radiation and ambient air temperature changes will no longer affect on ground temperature. It is one of the important parameters for designing of the ground heat exchangers and building energy analyses. In this study ground temperatures at various depths in Melbourne were investigated using a 40 m deep borehole instrumented with thermistors. The ground temperatures at various depths (0 m to 40 m) in Melbourne were also simulated by using three methods: Kasuda formula method, simulation (TRNSYS, Type 77), and simplified correlation (developed by Ouzzane et al. in 2015) and the results were compared with the measured data. Root mean square error (RMSE) and mean bias error (MBE) were used to validate and verify the methods. It was found that the estimated ground temperatures at 2, 21, and 40 m depths by Kasuda formula method and simulation (TRNSYS) have the same trends as that of the measured data. The measured annual temperatures of ground at 2 m depth were between 14.7 °C and 19.8 °C, while the temperature at 21 m and 40 m depths remained almost constant. RMSE and MBE of the simulation (TRNSYS, Type 77) were found to be 1.39 °C, and -1.39 °C respectively compared to measured data at 21 m depth. Based on these values, we conclude that simulation (TRNSYS, Type 77) can reliably predict the ground temperature for the selected site in Melbourne.

Paper ID:142

Effect of Backward Facing Step on the Aerodynamic Characteristics of NACA 0015 Airfoil

Md. Saadbin Chowdhury *; Musharrat Mustaree Mau , Md. Ibttihaz Shayok , Rafat Bin Mallick , Md. Ali

Bangladesh University of Engineering and technology, Bangladesh

Abstract:

The purpose of this research is to study the lift and drag characteristics of a NACA 0015 airfoil with a backward facing step. A backward facing step on the upper surface has the potential to improve the aerodynamic characteristics by reducing the drag coefficients and increasing the lift-to-drag ratios considerably. For a free stream velocity, the point of separation is determined by CFD analysis with increasing the angle of attack. A backward facing step is introduced just prior to the point of separation. The goal of improving the aerodynamic performance of the airfoil is inserted by searching the best configuration through gradually increasing the depth of facing step. A wind tunnel test on a NACA 0015 has been also conducted to verify the results from CFD analysis. The results show that reduction in drag is possible by separation delay with introducing the step. Though the reduction in lift has been observed, the lift to drag ratio also increases which is an important parameter in aerodynamic characteristics.

Paper ID:143

Feasibility Analysis of Municipal Solid Waste (MSW) for Energy Production in Rajshahi City Corporation

Pronob Das *; Md. Saiful Islam , Nurul Huda

RUET, Bangladesh

Abstract:

Bangladesh is a middle income, Southeast Asian developing country, facing an energy crisis, over population of 166 million, environmental pollution etc. that hinders her industrial as well as socio-economic development. Rajshahi is the 4th most populous city in the country having a population over 0.7 million faces the complexity of municipal solid waste (MSW) management issues. The conventional ways of treating them are landfilling and incineration in open airs that create shortage of land, water contamination, respiratory diseases, skin diseases and irritation of several organs etc. Proper use of these wastes towards power generation will not only solve the electricity scarcity of the country but also reduce the environmental pollution. The daily generation of MSW is estimated as 355 tons consisting of organic matter, paper, plastic, leather & rubber, glass, textile & wood and others.The present study represents a quantitative & comprehensive analysis of electrical power as well as biogas production from MSW for Rajshahi City Corporation (RCC). From this study, it is observed that about 8.5 MW electrical power or 3174.52 m3 biogas or 480 ton of LPG gas or 17 ton fired coal or 1587 L fuel oil could be extracted from MSW which will contribute to fulfill the increasing demand in RCC industrial development, making city more clean & green.

Paper ID:153

Harvesting of electrical energy from wasted heat from common household stoves using thermoelectric generators (TEGs)

Md Kharshiduzzaman *, Adnan Ibn Hossain , Aritra Rayhan ,Md Rubel Ahmed


Abstract:

Due to increasing concern of Environmental hazards coupled with the depletion of fuel sources has resulted in extensive research into new ideas and technologies of generating electrical power. Recent advancements in materials science has triggered research and investigation on waste heat energy harvesting techniques. Thermoelectric generators have emerged as a potential technology in that regard. Waste heat energy harvested using the thermoelectric generators (TEGs) are governed by the Thermoelectric, or Seebeck, effect, generating electricity from a temperature gradient. This work asks the question whether electricity can be produced from the wasted heat from household stoves commonly used in Bangladesh. For that, several tests were conducted by heating the Thermo Electric Cooler (TEC) cells on a Bunsen burner to predict its behavior during real operation and later, the developed characteristics patterns were applied, verified and improved by applying them on the cooking stoves. In order to do so, a new design consisting of bypass metal attached to TEC cell acting as generator unit for converting thermal energy into electrical energy has been introduced that utilizes the heat from burner flame. While using Aluminum Alloy of 10 cm length as bypass metal directly exposed to flame and without any heat sink attached to cell, 1.2 V was found at 80 seconds. On the other hand, 1.59 V was found while using Aluminum alloy of 10 cm length as bypass metal with heat sink attached to cell. The experiments were conducted under controlled room temperature and natural convection process. The main focus this study is the voltage output from our proposed generator unit. Also, another set of studies were conducted that gives us the idea of Power output from our setup. Both the outputs from this study might be utilized on light duty works required for household purposes.

Paper ID:155

A comparative numerical analysis of heat generation pattern for different materials at varying cutting speed

Monjur Mourshed, Md. Tariqul Islam *, Md. Towhidul Islam , Sami Ahbab Chowdhury

Rajshahi Uiversity of Engineering and Technology, Bangladesh

Abstract:

Dramatic variation of tool temperature while machining is treated as a considerable problem because it shortens the life of cutting edge which is considered as low durability of that part resulting in an adverse effect on the production. The excessive heat generated in the local cutting zone leads to thermal deformation, noticeable tool wear and low machining accuracy as well. In general, during highly precise machining operatios, it is necessary to determine the amount of process heat and heat fluxes into the work piece, tool and chips. This differs from various physical properties of tool including tool geometry, physical properties and for different operating conditions. Therefore, studying the thermal process and applying different material and cutting condition in cutting process has a practical importance from the point of view of understanding the intensity of deformation process in the cutting zone, the behavior of temperature distribution in the surface of cutting area, causes of tool failure and the quality of the machined surface. The aim of this research is to show an explicit overview of the nature of heat generation varying with different materials and cutting speed. In this study the cutting environment was designed in Solidworks Premium 2016 software and then it was simulated through Comsol Multiphysics 5.3 using thermoelastic physics interface. The analysis was observed for aluminum and cast iron as job material and high speed steel as cutting tool. The result found during analysis was about 9% more heat generation in cast iron machining compared to aluminum. It was also determined that the total temperature field of job material during cutting process changes with simultaneous change in cutting speed and feed rate. The results certified the endeavor of making a comparison between two dissimilar material for determining the optimum condition in production aspects.

Paper ID:157

Determination of the thermal conductivity of poor conductive materials in the form of disc by self-constructed Lee’s disc apparatus

Md Kharshiduzzaman *,Md. Saif Hossain , Soumik Ahmed ,Sazid Ali


Abstract:

Thermal conductivity is one of the most important properties for their engineering applications. In order to find out the conductivity of poor conductors, the material under investigation cannot be used in the form of a long bar just like the good conductors as the heat loss from the sides would be considerably high with respect to the heat actually conducted through the substance itself. In this regard, to determine the thermal conductivity of the poor conductors, specimens in the form of a disc were studied and conductivity was measured by applying Newton’s law of cooling. Thermal conductivity also depends on the anisotropic property of the material which indicates the observation of different values along different axes of same material. This work deals with the determination of thermal conductivity of different wooden specimens and reinforced composites made of jute fiber and chopped stranded mat of glass fiber by self-constructed Lee’s disc apparatus with compact electrical circuit instead of conventional steam chamber. For porosity in timber, the thermal conductivity of wooden specimens is low. Moreover, due to the aforementioned anisotropic property, the thermal conductivities of the wooden samples, both parallel and perpendicular to the grain were tested. It reflects that the thermal conductivities along the direction of the grain were greater than those parallel to the grain. Validation of the experimental data from the self-constructed apparatus was done by comparing the data achieved at Bangladesh Council of Scientific and Industrial Research which are in very good agreement. Afterwards, experiments for measuring thermal conductivity for jute fibre reinforced composites for six different ply configurations were carried out. It was observed that the thermal conductivities of hybrid composites i.e. those which consist plies of chopped strand mat of glass fibres were significantly less than those of the composites made of pure bi-directional jute mat.

Paper ID:163

Effect of Rayleigh Number Magneto-convection in a Lid Driven Square Cavity with a Sinusoidal wall

Md Shahidul Alam1 *, Abdul Alim2 , Shirazul Mollah1 , Mohammod Jahirul Haque Munshi3

1Dhaka University of Engineering & Technology, Bangladesh

2BUET, Bangladesh

3Hamdard University Bangladesh, Hamdard Nagar, Gazaria, munshiganj-1510, Bangladesh

Abstract:

In the present study the Effect of Rayleigh number magneto-convection in a lid driven square cavity with a sinusoidal wall were investigated numerically. The horizontal bottom and top walls are adiabatic. The left and right vertical walls are temperature Th and Tc respectively with Th>Tc. The governing equations along with appropriate boundary conditions for the present problem are first transformed into a non-dimensional form and the resulting non linear system of partial differential equations are then solved numerically using Galerkin’s finite element method. Parametric studies of the fluid flow and heat transfer in the enclosure are performed for Rayleigh number Ra, magnetic parameter Hartmann number Ha, sinusoidal λ, and Prandtle number Pr. The streamlines, isotherms, average Nusselt number at the hot wall and average temperature of the fluid in the enclosure are presented for the parameters. The numerical results indicate that the Hartmann number and Rayleigh number have strong influence on the streamlines and isotherms. On the other hand, Prandtl number has little effect on the stream line and isotherm plots. Finally, the mentioned parameters have significant effect on average Nusselt number at the hot wall and average temperature of the fluid in the enclosure.

Paper ID:165

MHD Effect on Mixed Convection Heat Transfer of Cu-Water Nanofluid in a Vented Parallelogrammic Cavity with Injection or Suction

Mohammod Jahirul Haque Munshi *

Hamdard University Bangladesh, Bangladesh

Abstract:

In this work MHD effect on mixed convection heat transfer of nanofluid in a vented parallelogrammic cavity with injection or suction is studied numerically using Cu-water nanofluid as working fluid. Galerkin weighted residual finite element method is used to solve the two dimensional problem. The bottom wall is subjected to be linearly heated temperature, while the other boundaries are considered thermally insulated. The pure water is admitted from the left vertical wall in bottom portion by injection or by the suction imposed on the opening of the right vertical wall. A set of graphical results are presented in terms of streamlines, isotherms, dimensionless temperature, velocity profiles and average Nusselt numbers to investigate the effect of Hartmann number, Reynolds number and Richardson number on the fluid flow and heat transfer characteristics inside the enclosure. The results demonstrate that heat transfer rate increases as increasing Richardson number. It is observed that Hartmann number is a good control parameter for heat transfer in fluid flow through parallelogrammic enclosure. Moreover, Cu-water nanofluid has significant effect to be used for enhancing the heat transfer rate. To validate the computational procedure present result compared with other published works.

Paper ID:168

A Comparative Study of Heat Formation in Various Metals Due to Different Types of Stresses Using Finite Element Analysis

Tariqul Islam *, Md. Towhidul Islam , Sami Ahbab Chowdhury

Rajshahi University of Engineering and Technology, Bangladesh

Abstract:

The process of heat generation or absorption in metals under stress is caused by intermolecular interaction taken place after applying external force. Quantity of generated or absorbed heat depends on the magnitude of the applied force and the induced stress. The relationship between the heat and stress is one of the basic material property that determines the failure of that specific metal. So, It is important to know the relationship between the stress and formation of heat in material while designing a product. Two basic parameters, material property and induced stress, determine the quantity of generated or absorbed heat. Again, induced stress determines the fact if heat would be absorbed or be generated. The aim of this study is to observe the generation of heat in different metals under different types of load condition. For the analysis, the chosen metals were Cast iron, Aluminum, AISI 4340 and Structural steel. These metals were chosen because of being widely used as engineering metals. The applied load conditions for the experiment were tension, compression and bending. The analysis was conducted using finite element technique in Comsol Multiphysics 5.3. The geometry of the metal was designed in Solidworks Premium 2016 and then imported in thermoelastic physics interface of Comsol Multiphysics. The loading conditions were varied to determine the relationship between the stress and generated heat and later compared with each other. The results show that the rate of generation of heat for AISI 4340 is greater than other metals at its ultimate strength. The temperature distribution shows that, the dissipation of temperature throughout the specimen is greater in aluminum than other three metals. These results will be useful in choosing metals that are to be used for fabricating devices employed in dynamic load condition.

Paper ID:191

Effect of Thermal Ageing on Dry-Sliding Wear Behavior of a Polymeric Matrix Material used in FRC Applications

Farhin Tabassum *


Abstract:

The dry-sliding wear and frictional behavior of a polymeric matrix material commonly used in fiber-reinforced composite applications are investigated as a function of thermal ageing temperature. More specifically, the commercially available polyester resin is used in this study to prepare disc-like samples of diameter 75mm and thickness 3mm, which are then aged isochronally at temperatures of 25°C, 75°C, 100°C and 125°C for a period of one hour. The wear test has been carried out against a high-speed carbon steel pin with a diameter of 5mm at a test load of 10N, in which the sliding distance is varied from 20m to 1450m with a sliding velocity of 0.4ms-1. The wear and frictional behavior of the polyester resin are found to be improved quite significantly when the samples are thermally treated at a temperature of around 125°C. At lower temperatures, softening of the polymeric sheet occurs due to minimum heat generation, which, in turn, results in a reduction of hardness and wear resistance. A surface investigation by scanning electron microscopic (SEM) images reveals that some casting defects are present in the form of pores in the original non-worn surfaces, whereas the worn surfaces are subjected to a resultant of severe plastic deformation and scuffing when the polyester resin samples are thermally treated at 125°C.

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Paper ID:199

Hall and Ion-slip Current Effect on Steady MHD Fluid Flow along a Vertical Porous Plate in a Rotating System

Mohammad Rafiqul Islam1 *, Md Alam Mahmud2



Abstract:

The steady MHD fluid flow of an incompressible electrically conducting fluid along an semi-infinite vertical porous plate under strong transverse magnetic field with rotation is considered. The system rotates about an axis normal to plane of the plate with angular velocity. The governing equations are partial non-linear coupled with joule heating, hall and ion-slip current. A similarity transformations have been used to obtain the nonlinear coupled ordinary differential equations from the above mentioned governing equations. The suction parameter is taken to be square of inversely proportional to this similarity parameter. Using perturbation technique, the momentum and energy equations are solved analytically. The results of velocity and temperature distribution are shown graphically. Finally, the comparison of our results and the published are shown graphically. Key words: MHD, Hall and ion slip current, porous plate, rotating system

Paper ID:207

Optimization of Sintering Profile to Achieve Highly Toughened Alumina Based Ceramic

Ummay Salma *,Md. Hasanuzzaman


Abstract:

Alumina (Al2O3) based ceramics are widely used for making machine parts, high-temperature components, wear-resistant material and biological ceramic due to their high hardness, strength, wear-resistance, and chemical and thermal stability. However, low fracture toughness (KIC ~ 3.0 MPa.m1/2) inhibit its usage in other potential applications where high toughness is a pre-requisite (e.g. ceramic engine). In an attempt to improve the strength, particularly the fracture toughness, two step sintering process was used. Sintering temperature was optimized based on the results obtained from dilatometer and DSC-TG analysis. X-ray fluorescence (XRF) was used to make compositional analysis of as received raw powders and X-ray Diffraction (XRD) was used to analysis the phase purity and crystallinity for both powder and sintered samples. Microstructure was investigated by using SEM. Hardness and fracture toughness values were measured and its correlation with microstructure was investigated. Density was measured by Archimedes method and crystalline density from XRD. Microhardness diamond indenter was used and the diagonal length of indent and the crack lengths were measured by SEM to calculate the Vickers hardness values and fracture toughness, respectively. The maximum fracture toughness was obtained 4.03 MPa.m1/2 for Al2O3 ceramic and the hardness value was 15.97 GPa. Density was found 98.9% of the relative density of Alumina at optimum sintering cycle and the grain size was found 0.39 µm. Thermal expansion coefficient was measured by dilatometer and the calculated value was 7.9×10-6 K-1. The physical properties of the Alumina were good enough and comparable to withstand high temperature applications.

Paper ID:208

Development of Antimicrobial Activity and Mechanical Performances of Cotton Fabric Treated with Silver Nano Particles (AgNPs)

Imana Shahrin Tania1 *; Md. Ali2 ; Zahidul Islam 3, Solaiman Solaiman2

1Bangladesh University Of Textiles, Bangladesh

2Bangladesh University of Engineering and technology, Bangladesh

3Bangladesh Council of Scientific And Industrial Research (BCSIR) , Bangladesh

Abstract:

The current research focuses on the synthesis, characterization and application of silver nano particles (AgNPs) on cotton fabric to create the antimicrobial property and improve its mechanical performances. Here nano particles are synthesized by reduction of salt in sol-gel method and applied on cotton fabric surface by mechanical thermo fixation technique. Various instrumental tests like UV spectroscopy, zetasize analyzing and scanning electron microscopy (SEM) are carried out to characterize the synthesized nano particles. The size of AgNPs is found about 60 nm and the shape is approximately spherical. The antimicrobial activity of treated fabric is examined against two bacteria named S. aureus (gram positive) and E. coli (gram negative) by bacterial reduction system. The result shows very good antimicrobial property in both gram positive and gram negative bacteria. An appreciable improvement on mechanical performances of nano treated fabric is also obtained.

Paper ID:214

Bingham Fluid Flow through Oscillatory Porous Plate with Ion-Slip and Hall Current

Md. Tusher Mollah1 *; Muhammad Minarul Islam1 , ferdows mohammad2 , Md Alam Mahmud3


2Unievrsity of Dhaka, Bangladesh


Abstract:

The numerical approach has been performed to study the Bingham fluid flow through an oscillatory porous plate with Ion-Slip and Hall current. Initially, at time t=0; both the fluid and the upper plate are at rest. At time t>0; the upper plate begins to oscillate in its own plane while the lower plate is stationary. The lower plate temperature is constant while the upper plate temperature has oscillated. A uniform magnetic field is applied perpendicular to the plates. To obtain the dimensionless equations from the governing non-linear partial differential equations, the usual transformations have been used. The explicit finite difference technique has been applied to solve the obtained dimensionless equations. The MATLAB R2015a has been used for numerical simulation. For the accuracy of the numerical technique, the stability and convergence criteria have been discussed. At the steady-state time, the effect of several parameters on the flow patterns, local shear stress and the Nusselt number have been shown graphically.

Paper ID:224

Effect of Filling Ratio and Adiabatic Length on Heat Pipe Heat Exchanger (HPHE)

Sakil Hossen*


Abstract:

Due to environmental concern and the high price of fuel, waste heat recovery has become a central issue for the industrial and commercial energy user. Waste heat recovery by heat pipe heat exchanger (HPHE) is an excellent way of saving energy and cost, preventing the global warming and reduction of air pollution. An HPHE generally consists of three sections: evaporation, condensation, and adiabatic section. From the different researchers, it has been experimentally found that filling ratio and variation of adiabatic section length has a great impact for increasing the thermal performance and effectiveness of HPHE. The main motivation of conducting this experimental work is to investigate the potential effect and heat transfer performance of heat pipe in a water-to-water HPHE by varying the filling ratio at 35%, 45%, 50%, 60% and 75% of heat pipe evaporation volume and changing the adiabatic length at 1/3rd, 1/4th and 1/9th of HPHE. Heat pipe was fabricated from the straight copper tube of 280 mm length (with an inner and outer diameter of 13 mm and 15mm) by a vacuum process and injecting the water as working fluid based on the thermosyphon principle. Best performance of the heat pipe was obtained for 50% filling ratio. Heat pipes with this optimal filling ratio chosen for constructing HPHE. The experiment was conducted without the adiabatic section that's replaced by a 2.5 mm metallic plate then it’s conducted by varying the length of the adiabatic section and also increasing and decreasing the condensation length. A water heater of 1000 W was placed in the evaporation section and atmospheric water was flown through the condensation section of the HPHE. The results show that both the filling ratio and appropriate consideration of the adiabatic section increase the thermal performance of HPHE. The shorter adiabatic length was found to enhance the performance of the heat pipe and best performance was found without adiabatic section.

Paper ID:226

3D Study of Heat Transfer Based On PVT/PCM System

M. Ashikuzzaman *, R. Nasrin, , F.T. Zohora , M.SADDAM HOSSAIN

Department of Mathematics, Bangladesh University of Engineering and Technology (BUET), Dhaka-1000, Bangladesh

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Abstract:

Electrical power as well as thermal energy are converted from solar radiation in a photovoltaic thermal (PVT) system. At a fixed temperature, thermal energy is absorbed by phase change materials (PCM) interms of latent heat. PCM has storage ability of latent heat. The heat is stored in PVT/PCM system and used latterly as an ultimate application. For PVT/PCM system heat removal procedure is concurrent due to the dependence of its charging and discharging on ambient. In this research, a 3D mathematical model of PVT/PCM system has been solved numerically using finite element method. Results have been shown interms of surface temperature and streamline pattern of PVT/PCM system with time variation. The values of average temperature of solar cell, electrical power, heat energy, electrical-thermal efficiency, and overall efficiency have been found. It is observed that using PCM in the PVT module the temperature of solar cell reduces and consequently the output power and efficiency enhance.

Paper ID:229

Experimental Analysis on Heat Transfer Performance of Cooling Tower with Nanofluid

Habibur Rahman1 *; Altab Hossain2 , Md. Ali3

1National Defence College, Dhaka, Bangladesh

2Military Institute of Science and Technology (MIST) , Bangladesh

3Bangladesh University of Engineering and technology, Bangladesh

Abstract:

Cooling towers have been widely used to dissipate heat by reducing temperature of hot water steam from heat sources to heat sink. However, the effectiveness of cooling tower depends on flow rates of air and water and water temperature. Hence, heat transfer process is very important since the heat comes from steam after spinning turbine must be removed otherwise the system will collapse due to overheating. Nanofluids are important coolant which provide new opportunities in excellent heat transfer performance, thus they can be regarded as the next-generation heat transfer fluids. The present study examined the effects of water and nanofluids as coolants on heat transfer coefficient, heat transfer rate, pressure drop and pumping power in the counter flow induced draft cooling tower and finding out the effect of adding toner as nanofluid to circulating cooling fluids. This was done by establishing and modifying experimental set up constructing computer program and varying the quality of circulating fluids by adding together at different ratio. Counter flow induced draft cooling tower and computer program give the various data required for calculation. From the result obtained a comparative study on terms of tower characteristics, water to air flow ratio (L/G), efficiency, range, percentage of make-up water and evaporation heat loss are presented in graphical form. It is estimated that efficiency and range increase by 8% & 4°c in average respectively. Furthermore, efficiency varies from 28.5 % to 39.15 % in case of cooling tower with water whereas with ink it is 42.55 % to 58.42 % which indicates the good performance of the developed system.

Paper ID:238

Noise Reduction of Helicopter Rotor Blades by Using Spoiler

Md. Tansirul Islam *

Chittagong University of Engineering & Technology, Bangladesh

Abstract:

Noise has always been a major disturbance for every living creature. Noise pollution is, thus, a threat to environmental pollution too. The noise created by a helicopter draws a great contribution to the noise pollution. Reducing the noise that creates from helicopter rotor blades, tail rotors, engine etc. is a one step closer to this crisis. Helicopter noise reduction is a topic of research into designing helicopters which can be operated more quietly. The major source of the noise come from the rotor blade vortex interaction. By attaching spoiler in the helicopter main rotor blades and tail rotors reduce the noise and silence the operation. The spoiler is made of supple, resilient, and durable non-ferrous material, such as rubber, a rubber like material, plastic, rubber impregnated with thin steel mesh, canvas reinforced rubber, rubber composites, and other durable materials that do not prematurely fatigue. The spoiler attached at the trailing edges of blades have free edges exhibits a non-repeating pattern of feather-like projections that collectively break up the vortex formed by blade rotation by providing clean air for each successive blade. The blade efficiency is also increased by using spoiler. This paper addresses the use of spoiler and comparison of noise level of rotor blades with or without spoiler.

Paper ID:242

A Hybrid Energy Harvester based on Solar Radiation and Mechanical Vibration

M Shafiqur Rahman *, Pratik Sarker, Uttam Chakravarty

University of New Orleans

Abstract:

In this study, a hybrid energy harvesting device is presented which simultaneously harvests energy from solar radiation and mechanical vibration using the photovoltaic, piezoelectric, and electromagnetic mechanisms. The device consists of a bimorph piezoelectric cantilever beam having Lead Zirconate Titanate (PZT) crystal patches on top and bottom surfaces of an Aluminum substrate. The tip of the cantilever beam has an attached permanent magnet which oscillates within stationary coils fixed to the top and bottom of a housing inside a casing. The exterior surface of the casing is covered by silicon photovoltaic panel that can capture energy from solar illumination. All the segments are interconnected by an electric circuit to generate a combined output when subjected to solar radiation and mechanical vibration. The hybrid prototype of the harvester is optimized by using finite element analysis to find the resonance frequencies and stress distributions. Results for power output are obtained at the resonance frequency of the hybrid beam using an optimum common load resistance. As the power outputs of all the mechanisms are combined, a high power output can be achieved by the proposed hybrid energy harvester.

Paper ID:245

Computational Analysis of Left Coronary Bifurcating Artery using Different Blood Rheological Models

Fahmida Laboni1 ,Md Foysal Rabbi1 , M Tarik Arafat2 *

1Military Institute of Science and Technology (MIST) , Bangladesh

2Bangladesh University of Engineering and Technology (BUET) , Bangladesh

Abstract:

A numerical study is performed to investigate hemodynamic factors using Newtonian and non-Newtonian blood viscosity models under pulsatile blood flow condition. In this study, simulation is done on 90⁰ bifurcating left coronary artery (LCA) by using Computational Fluid Dynamics (CFD). Comparative analysis is performed among one Newtonian and four non-Newtonian blood viscosity models. Wall shear stress (WSS), oscillatory shear index (OSI), global non-Newtonian importance factor (IG) and time-averaged wall shear stress (TAWSS) are shown at a specific point during the cardiac cycle. It is noticed that the pattern of WSS distribution is mostly consistent in all the models. However, the difference is only in the magnitude of WSS. For low inlet velocity, non-Newtonian power law predicts high WSS. However, for all inlet velocity conditions, Casson model predicts low WSS which is different from other non-Newtonian models. In moderate and high flow rates all the

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