Fakhar Title Defence_Final

8/2/2019 Fakhar Title Defence_Final

1/28
http://www.missionislam.com/islamicart/wallpaper/images/bismillah3_jpg_jpg.jpg


2/28

Thesis SupervisorDr. M. Afzaal Malik

Guidance & Evaluation CommitteeCol Dr. Syed Waheed-ul-Haq

Lt Col Dr. Aamer Ahmed Baqai

Mr. Raja Aamir Azim

MS Student

Fakhar-e-Alam Khan

2009-NUST-MSPhD-MECH-12
http://www.missionislam.com/islamicart/wallpaper/images/bismillah3_jpg_jpg.jpg


3/28

Sequence Motivation

Introduction

Research Plan Knowledge Base

Literature Survey

Development of Model/Sub-Models (Mathematical Equations)

Numerical Scheme

MATLAB Code Integration of all Sub-Models

Simulation of Results

Conclusions


4/28

Motivation Interest in Thermal Sciences/Internal Combustion

Engines.

I am working at a testing lab in a private sector commercial

organization. To look after Short Circuit Generator especially its

lubricating oil unit.

Lubricants make fluid film bearings reduce friction & wear,

and Provide load capacity.

That why I was keen to understand the Lubrication theoryof bearings and how heat affects its load carrying capacity.


5/28

Introduction The piston and top compression ring come into direct

contact with hot combustion gases.


6/28

Introduction (Contd) The heat energy in the piston is absorbed by the rings.

The rings then transfer this heat into the cylinderwalls.

Approx. 70% of the piston's heat is carried away by thepiston rings, under both unloaded and loaded engine

operation conditions, at 1,500 and 3,000 rpm.


7/28

Research Plan

Knowledge Base

Literature Survey

Development of Model/Sub-Models (MathematicalEquations)

Numerical Scheme

MATLAB Code

Integration of all Sub-Models

Simulation of Results Conclusions


8/28

Knowledge BaseWhole or part of the following books were studied:

Fundamentals of Fluid Film Lubricationby Bernard J.Hamrock & Steven R. Schmid

EngineeringTribologyby Gwidon W. Stachowiak & AndrewW. Batchelor

Elasto-HydrodynamicLubrication by D.Dowson &

G.R.Higginson AppliedTribologyby Michael M. Khonsari & E. Richard

Booser


9/28

Knowledge Base (Contd) ComputationalFluidDynamics by John D. Anderson, Jr.

ComputationalHeatTransfer by Yogesh Jaluria & Kenneth E.

Torrance HeatTransferCalculationsusingFiniteDifferenceEquations

by David R. Croft & David G. Lilley

InternalCombustionEngineFundamentals by John B.Heywood

ComputationalFluidDynamics(Volume)by Klaus A.Hoffmann & Steve T. Chiang


10/28

Knowledge Base (Contd) Mathematical Statements of Physical processes

(Differential Forms in Cartesian Coordinates):

Continuity Equation (Mass is conserved):

Conservation of Momentum (Momentum isconserved):

x-Momentum:

0)()()(

z

w

y

v

x

u

t

BxzxyxxxF

x

p

zyxz

uw

y

uv

x

uu

t

u

)()(


11/28

Knowledge Base (Contd) y-Momentum:

z-Momentum:

ByzyyyxyF

y

p

zyxz

vw

y

vv

x

vu

t

v

)()(

BzzzyzxzF

zp

zyxzww

ywv

xwu

tw

)()(


12/28

Knowledge Base(Contd) Energy Equation (Energy is conserved):

Reynolds's Equation:

The differential equation governing the pressure distribution in

fluid film lubrication is known as the Reynolds equation.

)()()()(

z

Tk

zy

Tk

yx

Tk

xz

Tw

y

Tv

x

Tu

t

TCp


13/28

Knowledge Base (Contd)

Couette term can further be expanded to:

expansionlocalsqueezenormal

squeezegeometric

sheartoduerateflownetterm:Couette

gradientspresuretoduerateflownet:termsPoiseuille

3

)(])([2

1

12 thww

x

hUhUU

x)

x

P

h(

xabbba

wedgedensity

wedgephysicalstretchphysical

sheartoduerateflownetterm:Couette

)(2

1)(2

1)(2

1])([2

1

xhUU

x

hUUUUx

hhUUx

babababa


14/28

Literature Survey Following journals were explored.

ASME Journal of Engineering for Gas Turbines and Power

ASME Journal of Heat Transfer

ASME Journal of Thermal Science and EngineeringApplications

ASME Journal of Tribology

SAE Technical Paper Series

SAGE Journal of Automobile Engineering Proceedings of IMechE

Elsevier Journal of Applied Thermal Engineering


15/28

Literature Survey (Contd) Journal of Tribology International

MIT MS/PhD thesis from dspace.mit.edu/

Bulletin of The Japan Society of Mechanical Engineers (JSME)


16/28

Literature Survey (Contd) Yasuo Harigaya, Michiyoshi Suzuki, Fujio Toda, Masaaki Takiguchi,

Analysis of Oil Film Thickness and Heat Transfer on a Piston Ring of aDiesel Engine: Effect of Lubricant Viscosity, ASME Journal of Engineeringfor Gas Turbines and Power, July 2006, Vol. 128/685.

Jordan A. Kaplan, Modeling The Spark Ignition Engine Warm-Up ProcessTo Predict Component Temperatures, MS Thesis, MIT, 1990.

Jordan A. Kaplan and John B. Heywood , Modeling the Spark IgnitionEngine Warm-Up Process to Predict Component Temperatures and

Hydrocarbon Emissions, SAE paper 910302, 1991.

V. Esfahanian, A. Javaheri, M. Ghaffarpour, Thermal analysis of an SIengine piston using different combustion boundary condition treatments,Applied Thermal Engineering 26 (2006) 277-287.


17/28

Literature Survey (Contd) Yong Liu and R. D. Reitz, Modeling of heat conduction within chamber

walls for multidimensional internal combustion engine simulations, Int. J.Heat & Mass Transfer, Vol. 41, Nos 6-7, pp. 859-869, 1998.

Ravindra Prasad and N. K. Samria, Transient heat transfer analysis in aninternal combustion engine piston, Computers & Structures Vol. 34, No.5,pp.787-793,1990.

Toshio TADA, Shoichi Furuhama, On the Heat Flow from the Pistons in a

Farm Type Gasoline Engine, Bulletin of JSME, 621.434-242:621.434.016.4.

Toshio TADA, Yoshitane OYA, Piston Temperatures of an AutomobileEngine, Bulletin of JSME, 621.434-242:621.434.016.4.


18/28

Mathematical Modeling

Energy Equation in Cylindrical Coordinates:

Energy Equation in Cylindrical Coordinates is:

In absence of motion and neglecting the source term , the

energy equation reduces to the governing equation for heatconduction in Piston Crown and Top Ring.

)()(

1)(

1)(

2 z

Tk

z

Tk

rr

Tkr

rrz

Tu

T

r

w

r

Tv

t

TCp

)()(1

)(1

2z

Tk

z

Tk

rr

Tkr

rrt

TCp


19/28

Energy Equation in Cylindrical

Coordinates (Contd)

Assuming constant thermal conductivity and

axisymmetry, the conduction heat equation is:

)()(

1

z

T

kzr

T

krrrt

T

Cp


20/28

Numerical Scheme Normally Closed form/exact solutions for real world

engineering problems do not exist.

Numerical Scheme is used.

Real world Engineering problems are mostly solved byusing any one of the following numerical schemes:

Finite Difference Scheme Finite Volume Scheme

Finite Element Scheme


21/28

Numerical Scheme (Contd) Finite Difference Scheme will be used.

Finite Difference Schemes are further classified asExplicit or Implicit Schemes.

Explicit schemes are easier to implement but these areconditionally stable schemes.

Implicit schemes are unconditionally stable schemes.


22/28

Numerical Scheme (Contd) 2-D Parabolic Partial Differential Equations are

normally solved by Alternating Direction Implicit(ADI) scheme.

Split the time step into half.

For the first half, treat one term implicitly while theother explicitly to get the solution by tridiagonal

algorithm. For the next half, reverse the implicit-explicit

formulation to again get the solution by tridiagonalalgorithm.


23/28

Numerical Scheme (Contd) Finite Differencing of 2-D Heat Equation using ADI

Scheme:

Let = Thermal Diffusivity

&

First Half:

pC

k

2)(

)(

r

trr

2)(

)(

z

trz

n

ji

n

ji

n

ji

n

ji

n

ji

n

ji Tr

rrrTrT

r

rrrTrTrTr

rrrrzzz ,1,,1

1

1,

1

,

1

1, )2

()21()2

()21(

Implicitz(j)Explicit,)( ir


24/28

Numerical Scheme (Contd) Second Half: Explicitz(j)Implicit,)( ir

1

1,

1

,

1

1,

2

,1

2

,

2

,1 )21()2

()21()2

(

n

ji

n

ji

n

ji

n

ji

n

ji

n

ji TrTrTrTr

rrrTrT

r

rrr

zzzrrrrr


25/28

Code Development Normally, simulation of results are obtained by using

Either Commercial Software

Writing Own Code in any Programming Language like C,FORTRAN, MATLAB etc

Due to strong graphics capabilities, the numerical

programming code is being written in MATLAB.


26/28

Integration of all sub-models The following equations will be coupled to get the

overall simulation results:

2-D Heat Equation in Piston Crown

1-D Heat Equation in Top Compression Ring

Convective Heat Transfer in lubricant film

Reynolds's Equation

Piston Dynamics Equation


27/28

Simulation of Results/Conclusions

Simulation of results will show the effect ofCombustion Heat over the load carrying capacity ofthe top compression ring.

Conclusions will be drawn from the above simulation

results.


28/28

Thank You

Documents

Fakhar Title Defence_Final