Hi, I am analyzing vortex shedding over an different 2d shapes. I have ansys 16 version (repsetvar 'les-2d? #t) TUI command is invalid.Please help to switch LES 2d in ANSYS 16 version.
LES in 2d has no physical meaning, you can only use 3D as for a DNS
Regards
Activate the LES turbulence model for 2D calculations: write with parenthesis: (rpsetvar 'les-2d? #t)
@ Ridha djebali.. I tried in 14.5 its working. But not in ANSYS 16. I have licence 16 only.So please help to switch LES 2D in ANSYS
if the rpvar does not work you could still create a 3D mesh in a single cell in the third dimension and apply symmetry on the boundary. It will be a pseudo 2D as you want but the mesh is 3D andthe LES model can be used
3D is impossible because of system constraints,. So doing 2D, if any possible to swith 2D in16.
LES in 2d has no physical meaning, you can only use 3D as for a DNS
Regards
Dear Rajasekarababu Kb,
I have ANSYS Fluent 16, I checked TUI command (rpsetvar 'les-2d? #t) and it is working. Although, I am agree with Dr Filippo Maria Denaro... It is suggested not to use LES in 2D...
Regards
Just to add that 2D turbulence is something that has some relevance in geophysical flows where the motion in the plane has large scales that are many order of magnitude greater than those in the third direction. In the book of Lesieur you can find a paragraph dedicated to this issue. All the other cases wherein "2D turbulence" is simulated consider particular geometries and boundary conditions where the flow is statistically 2D. In such cases the only possible approach is RANS.
LES in 2d is absolutely without any sense and physical meaning. Scale-resolved turbulence is a 3d phenomenon - always and not having any degree of symmetry.
I completely agree with other comments. True flowfield (especially the wake!) is 3D and a 2D LES will give a wrong answer since it neglects 3D effects(i.e.vortex stretching). A way to do it in 3D is required. Otherwise, RANS may be a better choice. Below animation demonstrates the three dimensionality of the problem:
https://www.youtube.com/watch?v=aR-hehP1pTk
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