CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Doubt Regarding SGS modelling in OpenFOAM

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 3, 2021, 21:25
Question Doubt Regarding SGS modelling in OpenFOAM
  #1
New Member
 
Hamza
Join Date: Jul 2021
Posts: 1
Rep Power: 0
CFDguy99 is on a distinguished road
Hello folks,

So I am using a compressible flow solver: rhoPimpleFoam and I am a using LES model (Smagorinsky) to measure the turbulent kinetic energy dissipation for the taylor green vortex problem. So initially, I ran my simulation as it is without making any changes to the solver and the peak dissipation that I obtained was at t*=5.5 (for 64^3 cells), t* = 6 (for 96^3 cells) and t* = 7 (for 128^3 cells) which is way away from what's mentioned in literature (t* = 9 for Re > 400, Brachet et al.).

So I made a modification and commented out the following line in the UEqn.H file (which is part of the rhoPimpleFoam solver):

// turbulence->divDevRhoReff(U)

I know that this function is responsible for calculating the shear rate tensor which in turn is used in modelling the Reynolds stresses but by commenting out this particular line, my results improved.

The peak dissipation that I now obtained was at t*=7.5 (for 64^3 cells), t* = 8 (for 96^3 cells) and t* = 8.5 (for 128^3 cells).

So my question is that by commenting out the above function, am I still modelling the subgrid stresses since the LES model has an implicit function for it or am I just ignoring all of the stresses and making my flow inviscid and not modelling the small eddies?

I appreciate any comment and would be grateful if one of you experienced OpenFOAMers could help me out!
CFDguy99 is offline   Reply With Quote

Reply

Tags
les, subgrid scale stresses

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Implicit vs Explicit SGS modelling syavash OpenFOAM Running, Solving & CFD 1 December 6, 2016 04:14
OpenFOAM Training, London, Chicago, Munich, Houston 2016-2017 cfd.direct OpenFOAM Announcements from Other Sources 0 September 14, 2016 03:19
OpenFOAM Foundation releases OpenFOAMŪ 3.0.0 CFDFoundation OpenFOAM Announcements from OpenFOAM Foundation 1 November 7, 2015 15:16
OpenFOAM Foundation Releases OpenFOAM v2.3.0 opencfd OpenFOAM Announcements from OpenFOAM Foundation 3 December 23, 2014 03:43
Modified OpenFOAM Forum Structure and New Mailing-List pete Site News & Announcements 0 June 29, 2009 05:56


All times are GMT -4. The time now is 11:53.