modeling and cfd analysis of radiator by using nano fluidsijpres.com/pdf35/49.pdf · automobile...

INTERNATIONAL JOURNAL OF PROFESSIONAL ENGINEERING STUDIES Volume 9 /Issue 2 / OCT 2017

IJPRES

MODELING AND CFD ANALYSIS OF RADIATOR BY USING NANO FLUIDS

1SUBBA REDDY.GANGIREDDY, 2KISHORE KUMAR.B 1 PG Scholar, Department of MECH, Nalanda Institute of Technology, Kantepudi,Sattenapalli

Dist.: Guntur,A.P, India,Pin: 522403

E-Mail Id: [email protected] 2HOD, Department of MECH, Nalanda Institute of Technology, Kantepudi,Sattenapalli

Dist.:Guntur,A.P, India,Pin: 522403

E-Mail Id: [email protected]

Abstract

Radiators are heat exchangersused to transfer thermal

energy from one medium to another for the purpose

of cooling and heating. The majority of radiators are

constructed to function in automobiles, buildings,

and electronics. The radiator is always a source of

heat to its environment, although this may be for

either the purpose of heating this environment, or for

cooling the fluid or coolant supplied to it, as

for engine cooling. Despite the name, most radiators

transfer the bulk of their heat via convection.

Automobile radiator main function is to cool the

engine by passing the coolant through cylinder water

jackets. The main objective of the project is to design

a radiator and assign aluminum and copper materials

to find out the better material for heat transfer. CFD

analysis is carried out to find the heat transfer

through the radiator.

Designing of radiator is done in solid works 2014

premium software. And cfd analysis is carried out in

solid works flow simulation tools.

Introduction

We know that in case of Internal Combustion

engines, combustion of air and fuel takes place inside

the engine cylinder and hot gases are generated. The

temperature of gases will be around 2300-2500°C.

This is a very high temperature and may result into

burning of oil film between the moving parts and

may result into seizing or welding of the same. So,

this temperature must be reduced to about 150-200°C

at which the engine will work most efficiently. Too

much cooling is also not desirable since it reduces the

thermal efficiency. So, the object of cooling system is

to keep the engine running at its most efficient

operating temperature. It is to be noted that the

engine is quite inefficient when it is cold and hence

the cooling system is designed in such a way that it

prevents cooling when the engine is warming up and

till it attains to maximum efficient operating

temperature, then it starts cooling. It is also to be

noted that: (a) About 20-25% of total heat generated

is used for producing brake power (useful work). (b)

Cooling system is designed to remove 30-35% of

total heat. (c) Remaining heat is lost in friction and

carried away by exhaust gases.

Cooling System for engine

A typical 4-cylinder vehicle cruising along the

highway at around 50 miles per hour, will produce

4000 controlled explosions per minute inside the

engine as the spark plugs ignite the fuel in each

cylinder to propel the vehicle down the road.

Obviously, these explosions produce an enormous

amount of heat and, if not controlled, will destroy an

engine in a matter of minutes. Controlling these high

temperatures is the job of the cooling system. The

modern cooling system has not changed much from

the cooling systems in the model T back in the '20s.

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Oh sure, it has become infinitely more reliable and

efficient at doing its job, but the basic cooling system

still consists of liquid coolant being circulated

through the engine, then out to the radiator to be

cooled by the air stream coming through the front

grill of the vehicle. Today's cooling system must

maintain the engine at a constant temperature

whether the outside air temperature is 110 degrees

Fahrenheit or 10 below zero. If the engine

temperature is too low, fuel economy will suffer and

emissions will rise. If the temperature is allowed to

get too hot for too long, the engine will self-destruct

WORKING OF COOLING SYSTEM

Actually, there are two types of cooling systems

found on motor vehicles: Liquid cooled and Air

cooled. Air cooled engines are found on a few older

cars, like the original Volkswagen Beetle, the

Chevrolet Corvair and a few others. Many modern

motorcycles still use air cooling, but for the most

part, automobiles and trucks use liquid cooled

systems and that is what this article will concentrate

on. The cooling system is made up of the passages

inside the engine block and heads, a water pump to

circulate the coolant, a thermostat to control the

temperature of the Cooling Systems in Automobiles

& Cars 689 coolant, a radiator to cool the coolant, a

radiator cap to control the pressure in the system, and

some plumbing consisting of interconnecting hoses to

transfer the coolant from the engine to radiator and

also to the car's heater system where hot coolant is

used to warm up the vehicle's interior on a cold day.

A cooling system works by sending a liquid coolant

through passages in the engine block and heads. As

the coolant flows through these passages, it picks up

heat from the engine. The heated fluid then makes its

way through a rubber hose to the radiator in the front

of the car. As it flows through the thin tubes in the

radiator, the hot liquid is cooled by the air stream

entering the engine compartment from the grill in

front of the car. Once the fluid is cooled, it returns to

the engine to absorb more heat.

Fig:1 Radiator

water pump has the job of keeping the fluid moving

through this system of plumbing and hidden

passages. A thermostat is placed between the engine

and the radiator to make sure that the coolant stays

above a certain preset temperature. If the coolant

temperature falls below this temperature, the

thermostat blocks the coolant flow to the radiator,

forcing the fluid instead through a bypass directly

back to the engine. The coolant will continue to

circulate like this until it reaches the design

temperature, at which point, the thermostat will open

a valve and allow the coolant back through the

radiator.

Circulation

The coolant follows a path that takes it from the

water pump, through passages inside the engine

block where it collects the heat produced by the

cylinders. It then flows up to the cylinder head (or

heads in a V type engine) where it collects more heat

from the combustion chambers. It then flows out past

the thermostat (if the thermostat is opened to allow

the fluid to pass), through the upper radiator hose and

into the radiator. The coolant flows through the thin

flattened tubes that make up the core of the radiator

and is cooled by the air flow through the radiator.

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From there, it flows out of the radiator, through the

lower radiator hose and back to the water pump. By

this time, the coolant is cooled off and ready to

collect more heat from the engine. The capacity of

the system is engineered for the type and size of the

engine and the work load that it is expected to

undergo. Obviously, the cooling system for a larger,

more powerful V8 engine in a heavy vehicle will

need considerably more capacity then a compact car

with a small 4-cylinder engine. On a large vehicle,

the radiator is larger with many more tubes for the

coolant to flow through. The radiator is also wider

and taller to capture more air flow entering the

vehicle from the grill in front. Antifreeze The coolant

that courses through the engine and associated

plumbing must be able to withstand temperatures

well below zero without freezing. It must also be able

to handle engine temperatures in excess of 250

degrees without boiling. A tall order for any fluid, but

that is not all. The fluid must also contain rust

inhibiters and a lubricant. The coolant in today's

vehicles is a mixture of ethylene glycol (antifreeze)

and water. The recommended ratio is fifty-fifty. In

other words, one-part antifreeze and one-part water.

This is the minimum recommended for use in

automobile engines. Less antifreeze and the boiling

point would be too low. In certain climates where the

temperatures can go well below zero, it is permissible

to have as much as 75% antifreeze and 25% water,

but no more than that. Pure antifreeze will not work

properly and can cause a boil over.

CLASSIFICATION

Types of cooling system in automobiles

There are mainly two types of cooling systems:

(a) Air cooled system, and

(b) Water cooled system.

Air Cooling System

Air cooled system is generally used in small engines

say up to 15-20 kW and in aero plane engines. In this

system fins or extended surfaces are provided on the

cylinder walls, cylinder head, etc. Heat generated due

to combustion in the engine cylinder will be

conducted to the fins and when the air flows over the

fins, heat will be dissipated to air. The amount of heat

dissipated to air depends upon:

(a) Amount of air flowing through the fins.

b) Fin surface area.

(c) Thermal conductivity of metal used for fins.

Water cooling system

In this method, cooling water jackets are provided

around the cylinder, cylinder head, valve seats etc.

The water when circulated through the jackets, it

absorbs heat of combustion. This hot water will then

be cooling in the radiator partially by a fan and

partially by the flow developed by the forward

motion of the vehicle. The cooled water is again re

circulated through the water jackets

Radiator

It mainly consists of an upper tank and lower tank

and between them is a core. The upper tank is

connected to the water outlets from the engines

jackets by a hose pipe and the lover tank is connected

to the jacket inlet through water pump by means of

hose pipes. There are 2-types of cores

(a) Tubular

(b) Cellular as shown. When the water is flowing

down through the radiator core, it is cooled partially

by the fan which blows air and partially by the air

flow developed by the forward motion of the vehicle.

As shown through water passages and air passages,

water and air will be flowing for cooling purpose. It

is to be noted that radiators are generally made out of

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copper and brass and their joints are made by

soldering.

Fig 2 Radiator

Basic Principleof Radiator

Most internal combustion engines are fluid cooled

using either air (a gaseous fluid) or a liquid coolant

run through a heat exchanger (radiator) cooled by air.

Marine engines and some stationary engines have

ready access to a large volume of water at a suitable

temperature. The water may be used directly to cool

the engine, but often has sediment, which can clog

coolant passages, or chemicals, such as salt, that can

chemically damage the engine. Thus, engine coolant

may be run through a heat exchanger that is cooled

by the body of water. Most liquid-cooled engines use

a mixture of water and chemicals such as antifreeze

and rust inhibitors. The industry term for the

antifreeze mixture is engine coolant. Some

antifreezes use no water at all, instead using a liquid

with different properties, such as propylene glycol or

a combination of propylene glycol and ethylene

glycol. Most "air-cooled" engines use some liquid oil

cooling, to maintain acceptable temperatures for both

critical engine parts and the oil itself. Most "liquid-

cooled" engines use some air cooling, with the intake

stroke of air cooling the combustion chamber. An

exception is Wankel engines, where some parts of the

combustion chamber are never cooled by intake,

requiring extra effort for successful operation.

However, properties of the coolant (water, oil, or air)

also affect cooling. As example, comparing water and

oil as coolants, one gram of oil can absorb about 55%

of the heat for the same rise in temperature (called

the specific heat capacity). Oil has about 90% the

density of water, so a given volume of oil can absorb

only about 50% of the energy of the same volume of

water. The thermal conductivity of water is about 4

times that of oil, which can aid heat transfer. The

viscosity of oil can be ten times greater than water,

increasing the energy required to pump oil for

cooling, and reducing the net power output of the

engine. Comparing air and water, air has vastly lower

heat capacity per gram and per volume (4000) and

less than a tenth the conductivity, but also much

lower viscosity (about 200 times lower: 17.4 ×

10−6Pa·s for air vs 8.94 × 10−4 Pa·s for water).

Continuing the calculation from two paragraphs

above, air cooling needs ten times of the surface area,

therefore the fins, and air needs 2000 times the flow

velocity and thus are circulating air fan needs ten

times the power of a recirculating water pump.

Moving heat from the cylinder to a large surface area

for air cooling can present problems such as

difficulties manufacturing the shapes needed for good

heat transfer and the space needed for free flow of a

large volume of air.

NANO FLUIDS

A nanofluid is a fluid containing nanometer-sized

particles, called Nanoparticles. These fluids are

engineered colloidal suspensions of nanoparticles in a

base fluid. TheNano particles used in nanofluids are

typically made of metals, oxides, carbides, or carbon

nanotubes. Common base fluids include

water, ethylene glycol and oil.

Nanofluids have novel properties that make them

potentially useful in many applications in heat

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transfer, including microelectronics, fuel cells,

pharmaceutical processes, and hybrid-powered

engines, engine cooling/vehicle thermal management,

domestic refrigerator, chiller, heat exchanger, in

grinding, machining and in boiler flue gas

temperature reduction. They exhibit

enhanced thermal conductivity and the

convective heat transfer coefficient compared to the

base fluid.[6] Knowledge of the rheological behavior

of nanofluids is found to be very critical in deciding

their suitability for convective heat transfer

applications Nanofluids also have special acoustical

properties and in ultrasonic fields display additional

shear-wave reconversion of an incident

compressional wave; the effect becomes more

pronounced as concentration increases.

In analysis such as computational fluid

dynamics (CFD), nanofluids can be assumed to be

single phase fluids. However, almost all of new

academic papers use two-phase assumption. Classical

theory of single phase fluids can be applied, where

physical properties of nanofluid is taken as a function

of properties of both constituents and their

concentrations. An alternative approach simulates

nanofluids using a two-component model.

The spreading of a nanofluid droplet is enhanced by

the solid-like ordering structure of nanoparticles

assembled near the contact line by diffusion, which

gives rise to a structural disjoining pressure in the

vicinity of the contact line. However, such

enhancement is not observed for small droplets with

diameter of nanometer scale, because the wetting

time scale is much smaller than the diffusion time

scale.

Applications

Nanofluids are primarily used for their enhanced

thermal properties as coolantsin heat transfer

equipment such as heat exchangers, electronic

cooling system (such as flat plate) and radiators. Heat

transfer over flat plate has been analyzed by many

researchers. However, they are also useful for their

controlled optical properties. Graphene based

nanofluid has been found to enhance Polymerase

chain reaction efficiency. Nanofluids in solar

collectorsis another application where nanofluids are

employed for their tunable optical properties.

SOLID WORKS

Solid Works is mechanical design automation

software that takes advantage of the familiar

Microsoft Windows graphical user interface.

It is an easy-to-learn tool which makes it possible for

mechanical designers to quickly sketch ideas,

experiment with features and dimensions, and

produce models and detailed drawings.

Introduction toSolidworks:

Solidworks mechanical design automation software is

a feature-based, parametric solid modeling design

tool which advantage of the easy to learn windows TM

graphical user interface. We can create fully associate

3-D solid models with or without while utilizing

automatic or user defined relations to capture design

intent.

Parameters refer to constraints whose values

determine the shape or geometry of the model or

assembly. Parameters can be either numeric

parameters, such as line lengths or circle diameters,

or geometric parameters, such as tangent, parallel,

concentric, horizontal or vertical, etc. Numeric

parameters can be associated with each other through

the use of relations, which allow them to capture

design intent.

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MODELING OF RADIATOR

Boss Extrude

Boss extrude on other side

fillet

Cut extrude

Linear pattern

Mirror

Thin – extrude

Fins dimensions for radiator

Final view of radiator

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Four different view of radiator

Finite Element Analysis

Finite Element Analysis (FEA) is a computer-based

numerical technique for calculating the strength and

behavior of engineering structures. It can be used to

calculate deflection, stress, vibration, buckling

behavior and many other phenomena. It also can be

used to analyze either small or large-scale deflection

under loading or applied displacement. It uses a

numerical technique called the finite element method

(FEM).

CFD FLOW SIMULATION

Computational fluid dynamics (CFD) is a branch

of fluid mechanics that uses numerical analysis

and data structures to solve and analyze problems

that involve fluid flows. Computers are used to

perform the calculations required to simulate the

interaction of liquids and gases with surfaces defined

By conditions. With high speed supercomputers,

better solutions can beachieved. Ongoing research

yields software thatimproves the accuracy and speed

ofComplexsimulation scenarios suchas transonicor

turbulent flows. Initial experimentalValidation of

such software is performed using a windtunnelwith

the final validation coming in full-scaletesting,

e.g. flight tests.

Solidworks Flow Simulation Introduction

Solid Works Flow Simulation 2010 is a fluid flow

analysis add-in package that is available for Solid

Works in order to obtain solutions to the full Navier-

Stokes equations that govern the motion of fluids.

Other packages that can be added to Solid Works

include Solid Works Motion and Solid Works

Simulation. A fluid flow analysis using Flow

Simulation involves a number of basic steps that are

shown in the following flowchart in figure.

Fig: Flowchart for fluid flow analysis using Solid

Works Flow Simulation

CFD ANALYSIS OF RADIATOR

General Settings CFD analysis

Water as fluid

Computational Domain

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BOUNDARY CONDITIONS

Inlet

Inlet temperature as 80-degree C

Material

Aluminum alloy

Outlet

Wall

Results and counters

Temperature

Pressure

Velocity

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TITANIUM OXIDE (TIO2)


The boundary conditions are same for all the fluids

which are selected.


Temperature

Pressure

Velocity

ALUMINUM OXIDE (AL2O3)


Fluid Properties of Al2O3

The boundary conditions are same for all the fluids

which are selected.


Temperature

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Pressure

Velocity

RESULTS

FOR WATER

FOR TiO2

FOR Al2O3

Fluid Inlet

temperature

(C)

Outlet

temperature(C)

Water 80 29.49

TIO2 80 26.26

AL2O3 80 26.22

Table: Results Table.

Conclusion:

Brief studies about radiators, types, working

are done in this project.

Studies about Nano fluids, applications are

done.

Modeling of Radiator is done by using solid

works 2016 software.

CFD analysis is performed on radiator by

using solid works Flow simulation module.

CFD analysis is performed on radiator by

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selecting three different fluid i.e. one regular

fluid water and two Nano fluid such as

Titanium oxide (TIO2) and Aluminum oxide

(Al2O3).

Boundary conditions is provided as 80-

degree C for inlet temperature of fluid,

which will have cooled by radiator pipe and

fins by means of convection process on

ambient temperature of 25-degree C.

Due to convection temperature of fluid flow

inside radiator will decrease, values

temperature, velocity and pressure of fluid

after analysis are noted and tabulated.

From result table, we can conclude that

Nano fluids give better convection i.e. gives

better cooling to engine compare to water.

Aluminum oxide (Al2O3) gives best result compare

to all fluid used for analysis.

References

1.V.L.Bhimani,.P.P.Ratho and

A.S.Sorathiya,“Experimental study of heat transfer

enhancement using water based nanofluids as a new

coolant for car radiators”.IJETAE Vol.3, Issue 6,June

2013.

2. Gaurav Sharma and Lal Kundan,” Experimental

investigation into thermal conductivity and viscocity

of Al2O3 based engine coolant”.IJRMET Vol. 3,

Issue 6,MayOct 2013.

3. Adnan M.Hussein , R.A.Bakar,

K.Kadirgama,G.L.Ming’ “Heat transfer augmentation

for the car radiator by using nanofluid”.MRE, ISBN:

978-1-63248-002 doi.

4. Rahul A.Bhogare and B.S.Kotahwale “A review

on applications and challenges of nanofluids as

coolant in automobile radiator “International journal

of scientific and research publications, volume

3,Issue 8, August 2013, ISSN 2250-3153.

5. Chavan D.K. and Tasgaonkar G.S. “Study

Analysis and Design of Automobile Radiator

Proposed with Cad Drawing and Geometrical Model

of the Fan” IJMPERD ISSN 2249-

6890, Vol 3, Issue 2, June 2013, 137-146.

6. Deepak Chintakayala and, Rajamanickam C.S.

“CFD analysis of fluid flow and heat transfer of an

automotive radiator with nano fluid “978-1-4673-

6150- 7/13/$31.00@2013 IEEE.

7. NavidBozorgan,

KomalaganKrishnakumar,NarimanBozorgan “

Numerical study on applications of CuO nanofluid in

Automotive Diesel Engine Radiator “ Modern

mechanical engineering 2012, 2,130-136.

8. Paresh Machhar and FalgunAdroja “Heat transfer

enhancement of automobile radiator with TiO2 and

water nanofluid “International journal of engineering

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Issue 5 may-2013.

9. RavikanthS.Vajjha ,DebendraK.Das , Praveen K

Namburu “Numerical study of fluid dynamic and

heat transfer performance of Al2O3 and CuO

nanofluids in the flat tubes of a radiator, International

Journal of Heat and Fluid Flow 31 (2010) 613-621.

10. QijunYu, Anthony G. Straatman Brian Thompson

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