[Elay]

Hello,

I've got a problem with programming an CFD-code using finite volume method. It's my first CFD project so I don't have got a lot of experience in it, but maybe anybody of you could help me.

Model data:
I've got a porous material with a gas sphere out of it, just one-dimensional but transient (burning problem), which should get a momentum at its outside, so the flow velocitiy there is for example 0.5 m/s.

There is existing a programmed code for a diffusion problem with no convective terms already. In it, its possible to solve systems of equations for temperature and the concentrations of substances or parameters like density, heat capacity and so on, which works very well.

My job is to realize this flow through the body. For this, i've got chosen the book 'An introduction to Computational Fluid Dynamics' (Versteeg and Malalasekera) which describes among other things the SIMPLE algorhitm for solving the navier-stokes-equation.
For the first step, I don't consider that the body is solid, just having a gas density.

But I don't know, whether the following is right:
First of all I guessed a pressure field (linear) and a velocity field (constant).
After this I programmed the coefficients AP, AW, AE and so on like it is written in the book for soliving the momentum equation. Is it now nessesary to solve this equation system for getting a new velocity field?
Or does I go on with the pressure correction directly by creating this coefficient d from Area/AP and so on and solving the pressure corrections with help of the continuity equation?



An other problem is the setting of the boundary condition. As I mentioned earlier at one side there is an inlet with a fixed velocity. The outhers i dont really know. One possibility would be to set pressure to 1 atm or 1 bar.
But where I have to set them in? By the momentum equation for calculating velosity oder on continuity equation for calculating pressure correction?
Or does I need 4 boundary conditions?



I hope I could explained it that you know what my problem is and I would be pleased if anybody is able to help me a little bit.
Thanks a lot!





I insert a lot of time in it untill now, but I didn't got some useful results.