CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Phoenics (http://www.cfd-online.com/Forums/phoenics/)
-   -   URGENT, CCM/MBFGE with GENTRA (http://www.cfd-online.com/Forums/phoenics/51172-urgent-ccm-mbfge-gentra.html)

Javier Larrondo March 12, 2001 20:28

URGENT, CCM/MBFGE with GENTRA
 
Is it possibly to combine GENTRA with a mutliblock grid?

I have found the following sentence in POLIS:

"At present CHEMKIN, GENTRA, stresses in solids model and radiation model based on the view-factors calculation are not available for use with CCM/MBFGE. "

in this location: c:/phoenics/D_POLIS/D_ENC/MULTI.HTM#3.9

But, we have a report of our client, with a simulation of particle traking with a multiblock case, done by other company using Phoenics.

Please help, i'm in a hurry...

thanks for all

Javier


Mike Malin March 13, 2001 08:52

Re: URGENT, CCM/MBFGE with GENTRA
 
GENTRA predates the introduction of the CCM/MB method into PHOENICS, and CHAM has made no modifications since then that would allow GENTRA to be used correctly on CCM-MB grids. I imagine it might be possible for a user to make it so by means of GROUND and/or GENIUS coding, or by even writing their own particle-tracking module for the calculations.

If a user has adapted the existing GENTRA for CCM-MB grids, then they would have had to consider at least the following factors:

a) GENTRA puts the interphase momentum sources into the control volumes of the staggered covariant velocity variables U1, V1 and W1. However, CCM solves for the covariant velocity variables UC1, VC1 and WC1 on a co-located mesh.

b) GENTRA uses the Cartesian velocities UCRT, VCRT and WCRT for the continuous-phase velocity vector. Perhaps these are retained for CCM, but their storage locations may differ, i.e. staggered versus colocated momentum equations.

c) For multi-block meshes, the tracking algorithm must be modified so as to recognise when a particle moves from one block into the next block. This would be a major modification requiring great care to ensure correct implementation.



All times are GMT -4. The time now is 16:36.