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rolf June 10, 2010 07:02

FVM Euler Wall boundaries
 
Hi.

I'm implementing the Euler equations for unstructured grids following the method of the Versteeg book (with some input from other sources). It is now running around an airfoil.

The inlets and outlets appear to work nicely (as the uniform flow problems run correctly), but the wall conditions introduces some problems.

First of all, should the momentum equations return values that correspond to a tangential flow? It does not here, after updating the pressure and velocities with the pressure corrections, it does to some extent (depending on the relaxation factor).

The system also blows up after 2 iterations. I'll attach a screenshot after the first iteration.

http://folk.ntnu.no/klungsoy/cfd/airfoil.jpg

Any idea what could be wrong? And also, should the pressure correction equations etc treat the ghost cells as regular cells? (I do that now, though reset the velocities, pressure etc at the start of each iteration corresponding to the boundary cell).

- Rolf

Dhileep T K June 10, 2010 08:02

Hi
 
Hi.
I dont know the answer for your question (sorry for that).
I am having a book writte by versteeg which deals completely with structured grids. i want to learn about unstructured grids.. can you share with me the book which you are using for unstructured grids.

rolf June 10, 2010 08:20

We are probably using the same book, "An introduction to Computational Fluid Dynamics: The Finite Volume Method", second edition. Take a look at chapter 11, which covers complex geometries. That should get you started.

There are many other books that cover the topic, though. I've also used books by Ferziger, Blazek, a phd thesis by Hadzic etc.

Dhileep T K June 11, 2010 07:01

Hi
 
Thank you for the reply. I am having only the first edition of that book. Do you have any link to the second edition of the book so that i can download it. Thanks in advance.


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