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-   -   Deciding on Time step size? (http://www.cfd-online.com/Forums/star-ccm/82302-deciding-time-step-size.html)

sreenivas November 23, 2010 01:58

Deciding on Time step size?
 
HI
How can we generally decide on Time step size?Especially when applied to usteady heat transfer problems
is this physics dependent? or mesh dependent?
can anybody give me the detailed explanation on choosing the time step sizes

Thanks in Advance

Srinivas

Larsen November 27, 2010 22:32

It is both physics and mesh related. The speed of which the air is moving and the resolution decides on the time step. You goal is to keep the air from moving through more than one cell per time step.

Try setting up a scalar scene with the most important flow plane (Symmetry plane etc.). Select covectic concurant number as function and adjust the timing until most cells are < 1


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