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-   -   timestep in transinet simulations (http://www.cfd-online.com/Forums/cfx/21174-timestep-transinet-simulations.html)

caty April 18, 2005 18:19

timestep in transinet simulations
 
Hello everybody,

I have a question regarding the timestep in a transinet simulation.

I am simulating combustion and in same points the tempertures seems to jump very easy from one small value to a big one and after that jumped back, which is not the case in reality.

The convergence in satisfactory < 1e-4 owith each timestep.

My question is if the large variations of temperature (this doesnt appear at the start of the simulation) are due to the size of timestep, too big maybe??

How can i know which is the most appropriate timestep???

caty

Glenn Horrocks April 18, 2005 19:54

Re: timestep in transinet simulations
 
Hi,

Test various timestep sizes and find out. There is no simple answer, some combustion requires very short timesteps and some can handle quite ong timesteps. Also it may be helpful to also converge on imbalances as well - again try it and see if it helps.

Glenn Horrocks


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