introduction to fluid flow

8/3/2019 Introduction to Fluid Flow

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Introduction Fluid flow/fluid dynamic a branch of f luid mechanics

Aerodynamics - the study of air/other gases in motion

Hydrodynamics - the study of liquids in motion

Application

Calculation of forces and moments on aircraft

Determining mass flow rate of petroleum through pipeline

Traffic engineering? Make sense? How?

Traffic is treated as continuous liquid

Solution of fluid flow (dynamic) involves calculation ofvarious properties of fluid as functions of space and time


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Types of Fluid Compressible vs Incompressible

All fluids are compressible to some extent (changes in pressure, P andtemperature, T will results in changes in density)

In many situations, changes in P and T are small, changes in density is

negligible

incompressible fluid Laminar vs Turbulent

Turbulence is flow characterized by recirculation, eddies andrandomness

Flow which is not turbulent is Laminar Newtonian vs Non-newtonian

A non-Newtonian fluid is a fluid whose flow properties are notdescribed by a single constant value of viscosity

Example: as ketchup, starch suspensions, paint, blood and shampoo Newtonian fluid, the relation between the shear stress and the strain

rate is linear water and air


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Types of Fluid Flow Cavitation Compressible flow Couette flow Free molecular flow

Incompressible flow Inviscid flow Isothermal flow Laminar flow Open channel flow Secondary flow

Superfluidity Supersonic Transient flow Transonic Turbulent flow Two-phase flow

Find all the meaning of these termsand provide examples


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Fluid Phenomena Boundary layer Coanda effect Convection cell Convergence/Bifurcation Drag (force) Hydrodynamic stability Lift (force) Ocean surface waves Rossby wave Shock wave Soliton

Stokes drift Turbulence Venturi effect Vortex Vorticity Water hammer Wave drag

Find all the meaning of these terms and provide examples


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Flow of Fluids Concerned with the transport of fluid from one

location to another through pipes/open ducts

Requires determination of pressure drop in thesystem, power required for pumping &measurement of flowrates

In many cases, fluid contains solid particles insuspension, necessary to determine the effect ofthese particles on the flow characteristics


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Internal Energy Internal energy The energy which is attributableto the physical state of fluid

When a fluid flows from one location to another,energy will be converted from one form to another

Change in physical state of fluid will cause changein internal energy

*Derive energy of a fluid in motion


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Fluid in MotionWhen a fluid flows through a duct or over a

surface, the velocity over a plane at right angles to

the stream is not normally uniform The flowrate between any two streamlines is the

same

Closer spacing of the streamlines represents an

increase in velocity

A group of streamlines form streamtube, wholearea for flow composed of bundles of streamtubes


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Flow Through Surface

introduction to fluid flow

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