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 happysmile March 14, 2009 12:14

Need a help concerning a pure convection problem

Hello all.

I am studying a book entitled 'An Introduction to CFD : FVM approach' by versteeg.

I found two dimensional pure convection problem with discontinuity, and QUICK solver was developed for that problem.

However, my code blowed up in the middle of running. I think source term of the discretized equation is so big which cause the system of the discretized equation to be unstable.

Is there anyone who have an experience to deal with my trouble?

I have a document of the relating equations and numerical descriptions and i can share if leaving e-mail address.

Regards.

 harishg March 15, 2009 20:44

What was the time marching scheme that was employed ? The explicit schemes have issues with stability. Did you test your code for a simple case like 1-D shock tube problem to check the implementation.

 9mile March 15, 2009 22:26

My code use space marching called line-by-line method mentioned in chapter 7 of the book. I think the method may be implicit.
What is your opinion applying line-by-line method with QUICK to pure convection problem?
I think my discretized equation applied by QUICK is ok but next step related to line-by-line method is not sure whether is good or bad in this case.
Do you have any suggetions to marching method?
Now, i'm trying to implement relaxation technique but i can not be sure what results i'll get because the author does not mention in the book which marching method he used.
Also i'll consider 1-D shock tube problem.

 Far March 16, 2009 08:55

scheme

which scheme you are using for pressure correction

 9mile March 16, 2009 10:48

It doesn't need any pressure correction.
The governing equation is as follows.

rho*u*(partial phi)/(partial x) + rho*v*(partial phi)/(partial y) =0

And each of face value for 'phi' in FVM is applied by QUICK method and for multi-dimension, line-by-line method is used.

That's all.

If it has discontinuities you can use CICSAM scheme.

 Nishu July 8, 2009 13:24

Hi,

Can someone send me the 1D code for shock tube problem at babuu.nishu@gmail.com? I need it for my research.

Thanks alot
Nishant

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