LES/DNS grid size time step dependancy

mörli · July 25, 2019, 08:41

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.

FMDenaro · July 25, 2019, 11:34

Quote:

Originally Posted by mörli

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.

July 25, 2019, 08:41	LES/DNS grid size time step dependancy	#1
mörli New Member Join Date: Mar 2019 Posts: 11 Rep Power: 7	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.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
[Other] Contribution a new utility: refine wall layer mesh based on yPlus field	lakeat	OpenFOAM Community Contributions	58	December 23, 2021 02:36
LES, Courant Number, Crash, Sudden	Alhasan	OpenFOAM Running, Solving & CFD	5	November 22, 2019 02:05
pimpleDyMFoam computation randomly stops	babapeti	OpenFOAM Running, Solving & CFD	5	January 24, 2018 05:28
Superlinear speedup in OpenFOAM 13	msrinath80	OpenFOAM Running, Solving & CFD	18	March 3, 2015 05:36
Could anybody help me see this error and give help	liugx212	OpenFOAM Running, Solving & CFD	3	January 4, 2006 18:07