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-   -   Modify the geometry and mesh during a simulation (http://www.cfd-online.com/Forums/star-ccm/111573-modify-geometry-mesh-during-simulation.html)

virgy January 10, 2013 05:29

Modify the geometry and mesh during a simulation
 
Hi!
I have a generic question:
I start a steady-state simulation with a given geometry, after some iterations I stop the simulation and I modify the geometry and therefore the mesh, then I re-start the simulation without deleting the old fields of the solution. Can this operation affect the right final solution?



I'm relatively new in Star-CCM+, I know it's possible with Star-CCM+ acting in this way and this is the advice of some people more expert than me: so in this way you can use the previous results and you don't lose precious computational time.


However I sometimes realize that this way can create "some hassles and difficulties" to obtain the convergence.



To expert of CFD: Are you agree with that advice?
I know that it could be depend on the type of geometry, mesh, physics.... but have you any guidelines for me?



Thanks for every suggestions, I appreciate a lot.
:)

abdul099 January 10, 2013 15:55

When it's a stationary simulation, it will have NO influence on the final, converged solution. Remeshing is often done to run a modified geometry and start from a solution which is much closer to the final solution than a relative simple initialization. This saves computing time and hence often (but not always) makes sense.

When it's a stationary simulation, you would change the physics by changing the geometry. When you need the time-dependent course, you shouldn't modify your geometry unless that's the real behaviour.


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