Re:

[Daniel Wheeler]

Hi, I have added an example to FiPy that solves the Stokes equations in a cavity using the SIMPLE algorithm for pressure-momentum coupling. The example is in examples/flow/stokesCavity.py. You will need to use CVS to access it. It won't work with older versions of FiPy. We are hopefully of making release 1.1 of FiPy soon so you could hang on until then if you don't want to use CVS.  The results were compared with the open source Dolfyn code. Dolfyn has some special features related to flow that FiPy does not have. When these features are switched off, the results are identical. The example file has details of the errors when the special features are on. In order to get FiPy to match Dolfyn results (with special features on), I still need to add the following,         - higher order spatial discretization for the diffusion term    - wall boundary conditions    - improved mass flux evaluation that includes some pressure component    - extrapolation of cell center values to boundaries The above will be added over time and also some more interesting flow examples. If anyone else feels like implementing some of this in the mean time feel free. Hope this helps... - Dolfyn (www.dolfyn.net) On Apr 5, 2006, at 9:15 AM, GREUILLET Nicolas wrote: Hi   I’m working on numerical simulation of the welding processes. More precisely,  my  work deals with the simulation of the weld pool and I would like to use Fipy to do this. To achieve, I have to solve the coupled Navier Stokes (momentum), energy and mass conservation equations . The main issue is the fact that pressure and velocity are linked in the momentum equation. I consider only the steady state. That is why I would like to implement the SIMPLE algorithm to get a velocity field satisfying both the mass conservation and momentum equation and the correct pressure field. I’ve been trying to implement this algorithm with Fipy’s basic tools for 2 weeks unsuccessfully and finally, I wonder if it is possible. Can anybody help me?   Nicolas               ------------------------------------- Daniel Wheeler Telephone: (301) 975-8358