1.mkm 411-lecture feb. 4th

8/13/2019 1.MKM 411-Lecture Feb. 4th

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February 4th

COMPUTATIONAL FLUID

DYNAMICS (MKM411)

[email protected]

Dr. M. Sharifpur

Department of Mechanical and Aeronautical Engineering

University of Pretoria

2014


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General InformationStudy Guide ClickUP

My consulting (office) hours:Mondays; 12:30-13:30

Tuesdays; 12:00-13:00

or any other time by booking an appointment

[email protected]

Calculation of Semester Mark:

Semester test 1 35%

Semester test 2 35%Assignments 20% Randomly selected questions

Unannounced class tests 10% one will be dropped


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Practical Sessions for the CourseOn the timetable;

Mondays; 10:30 to 12:30 (Eng III4)

Lecturesand Assignments will be posted on clickUP on Fridays

Examples are within thelectures while we have Unannouncedclass tests.

On Mondays, from 10:30 to 11:30 , two Teaching Assistants willbe available for your queries about assignment.

Instead of Practical , CFD Software Training Courses(ANSYS-FLUENT, STAR CCM+ and FLoEFD)

The Schedule will be announced


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Semester Project

(ANSYS-FLUENT, STAR CCM+ or FLoEFD)

The project markwill notbe involved in the

semester or final mark, but ECSA outcome.

Achieving 50% of the assessment matrix for ECSA

exit level outcome 5 is oneof the requirements in

order to passthe course.


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Assessment matrix for ECSA exit level outcome 5

Description Reference

Able to apply verification and validation to

an engineering problem

Homework

(20%)

Able to list and apply the various

steps in a computational fluid

dynamics simulation

Semester tests

(20%)

Able to analysis, solve and post processing

an engineering problem using acommercial computational fluid dynamics

package

Semester Project

(60%)

Mark50


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Prescribed text books

An introduction to Computational Fluid Dynamics:

The Finite Volume Method,

Versteeg, H.K. and Malalasekera, W., 2007

Heat and Mass Transfer: fundamentals &

applications (SI Unit),

engel, Yunus A.;Ghajar, Afshin J.


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Lecture and module structureCOMPUTATIONAL FLUID DYNAMICS (CFD)

Conservation laws, Initial and Boundary Conditions

MKM320, MTV310

Finite Difference Method (FDM)Finite Volume Method (FVM)

CFD Software Training Courses

(ANSYS-FLUENT, STAR CCM+ and FLoEFD)

Any questions about the course?


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Why Continuum Mechanics?

The subject of mechanicsdeals with the study of

motion and forces in solids, liquids and gases

by simplifying assumption , for analysispurposes, that the matter is distributed

continuously, without gapsor empty spaces.

Whydo we need to assume matter is distributed

continuously foranalysis purposes?

Continuum Mechanics;


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For analysiswe need to formulatewith

mathematics

A problem/idea which you can't formulate withmathematicsis useless!How can you make predictionswith it if you cant formulateit ?

How can youtest an idea if you can't make predictions?

In Engineering and Science


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M=?

Example (example 1-10, Fluid Mechanics by White)

A=r

THERMOFLUIDS MTV310


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Therefore, we already assumed

that the matter is distributed

continuously, without gapsor

empty spaces in differentcourses


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Predictions

If we formulate a fact we can predictfor different conditions


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Even in two-phase flow we can assume Continuous

Media,but by applying a conversion factor


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Computers and Humans

"Computersare incredibly fast,accurate, and stupid;

humansare incredibly slow,

inaccurateand brilliant;togetherthey are powerful

beyond imagination."

1921 Nobel Prize in Physics for photoelectric effect. In 1999 Einstein

was named Timemagazine's "Person of the Century", and a poll of

prominent physicists named him the greatest physicist of all time.

h d l bl ?


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First order linear differential equation

Exact Analytical Solution;

Example;

Simple

Engineering

Problem

Problem

Solution

t is a variable

Analytical Solution

When do we use computer to solve an Engineering problem?


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Complex

EngineeringProblem

Problem

Solution

1- Approximate Solution

2-Numerical Solution

When do we use computer to solve an Engineering problem?


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)(

)),((

i

i

TT

TtxT

2

2

1T T

x t

2

2

X

L

xX

For example; One-dimensional transient heat conduction (and no

heat generation)

After changing the variables tonon-dimensional form

t

Tce

z

Tk

zy

Tk

yx

Tk

x gen


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2

1

4sin cos2 sin 2

nnn

n n n

e X

General Solution for

2

2

X

chL

Bi k

A set of solution


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ComplexEngineering

Problem

Problem

Solution

Approximate SolutionOR

Numerical Solution

t

Tce

z

Tk

zy

Tk

yx

Tk

x gen

What about Three-dimensional transient heat conduction with heat

generation


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Wrong Info

Wrong Initial & BC

Wrong Output

The important issue is:The problem The answer

Did you solve theright problem?

Numerical Solution

Programing (writing a code)

Using Software

OR


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Engineering

Problem

Finding;

- Governing (Differential) Equations

- Initial & Boundary Conditions

Therefore, we must find the Governing Differential Equations,

After that, Simplifying the Governing Differential Equations

regarding the physics of problem

and also choosing right Initial & Boundary Conditions

-Analytical Solution

-Numerical Solution (Programing)

- Using a Software

Mathematics Review

Continuum Mechanics

Fluid Mechanics

Heat Transfer


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Mathematics ReviewHow many Derivatives do we have?

Partial Derivative

Material Derivative

Lagrangian DerivativeEulerian Derivative

Substantial Derivative

Total Derivative

Particle Derivative

What are the differences between them?

t

U

dt

dU

Dt

DU

?

?

dt

dU

or

Dt

DU

1.mkm 411-lecture feb. 4th

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