Free shear flow LES/DES, SAS, RANS

laxwendrofzx9r · March 23, 2013, 20:48

HI, I spent quite a lot of time trying to find some informations about mesh requiments for LES/DES, SAS and RANS turbulence methods for free shear flow. Unfortunately I can not find any good examples and meshes for such kind of the flow. If somebody can help and give a general overview and rules about mesh sizes would be great for such type of flow.

My assumption is: air-jet around 60m/s dissipated into the region of 20mx40mx100m .

Any idea about mesh, cell size for DES or SAS or RANS?

kalyangoparaju · March 23, 2013, 20:57

I do LES on jet flows and generally, the mesh sizes range any where from 6 mil to 20-30 mil depending on the resources. A good size would be around 6-10 mil .

FMDenaro · March 24, 2013, 05:45

better thinking about normalized sizes ... a characteristic lenght can be the scale of the boundary layer. In free-wall flows, you can stay in terms of a mesh Reynolds about 20 - 30

March 23, 2013, 20:48	Free shear flow LES/DES, SAS, RANS	#1
laxwendrofzx9r New Member mirion Join Date: Dec 2010 Posts: 24 Rep Power: 15	HI, I spent quite a lot of time trying to find some informations about mesh requiments for LES/DES, SAS and RANS turbulence methods for free shear flow. Unfortunately I can not find any good examples and meshes for such kind of the flow. If somebody can help and give a general overview and rules about mesh sizes would be great for such type of flow. My assumption is: air-jet around 60m/s dissipated into the region of 20mx40mx100m . Any idea about mesh, cell size for DES or SAS or RANS?

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March 23, 2013, 20:57		#2
kalyangoparaju Member Kalyan Join Date: Oct 2011 Location: Columbus, Ohio Posts: 53 Blog Entries: 1 Rep Power: 15	I do LES on jet flows and generally, the mesh sizes range any where from 6 mil to 20-30 mil depending on the resources. A good size would be around 6-10 mil .

March 24, 2013, 05:45		#3
FMDenaro Senior Member Filippo Maria Denaro Join Date: Jul 2010 Posts: 6,882 Rep Power: 73	better thinking about normalized sizes ... a characteristic lenght can be the scale of the boundary layer. In free-wall flows, you can stay in terms of a mesh Reynolds about 20 - 30