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LES/DNS grid size time step dependancy

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Old   July 25, 2019, 09:41
Default LES/DNS grid size time step dependancy
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Hi everyone,


I was wondering if you can determine a reasonable timestep for a given grid size or vice versa only considering the resolved eddies. Hence I was looking for a dependency of time (or velocity) scale on length scale but could not find anything helpful except for the smalles eddies dissipating the energy.


Thanks for any hints.
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Old   July 25, 2019, 12:34
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Quote:
Originally Posted by mörli View Post
Hi everyone,


I was wondering if you can determine a reasonable timestep for a given grid size or vice versa only considering the resolved eddies. Hence I was looking for a dependency of time (or velocity) scale on length scale but could not find anything helpful except for the smalles eddies dissipating the energy.


Thanks for any hints.



Given the grid size, both in LES and DNS the time step is very low both for numerical stability and accuracy.
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