CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS

LES simulation

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

Like Tree4Likes
  • 1 Post By zagros135
  • 1 Post By Светлана
  • 1 Post By Светлана
  • 1 Post By alainislas

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 2, 2022, 04:05
Default LES simulation
  #1
New Member
 
zagros
Join Date: Apr 2022
Posts: 19
Rep Power: 3
zagros135 is on a distinguished road
hello to everyone.

I'm new in ansys and I want to simulate an oscillating airfoil with LES and dynamic mesh. But I did not find any training in this field. Can you advise me what to do?
lucedar likes this.
zagros135 is offline   Reply With Quote

Old   May 5, 2022, 03:15
Default
  #2
Senior Member
 
Svetlana Tkachenko
Join Date: Oct 2013
Location: Australia, Sydney
Posts: 407
Rep Power: 14
Светлана is on a distinguished road
is it for uni, for internship, or what is the context of this effort? did you do cfd before? thanks
zagros135 likes this.
Светлана is offline   Reply With Quote

Old   May 7, 2022, 02:06
Default
  #3
New Member
 
zagros
Join Date: Apr 2022
Posts: 19
Rep Power: 3
zagros135 is on a distinguished road
Quote:
Originally Posted by Светлана View Post
is it for uni, for internship, or what is the context of this effort? did you do cfd before? thanks
Its for university. I want to do a simulation like the below article in Reynolds less than 100 thousand.

link:https://www.sciencedirect.com/scienc...42727X19307593

yes. I did simulations 2D-steady with kwsst and k epsilon before. But I don't know about les and transient settings.
zagros135 is offline   Reply With Quote

Old   May 16, 2022, 04:28
Default
  #4
Senior Member
 
Svetlana Tkachenko
Join Date: Oct 2013
Location: Australia, Sydney
Posts: 407
Rep Power: 14
Светлана is on a distinguished road
Quote:
Originally Posted by zagros135 View Post
Its for university. I want to do a simulation like the below article in Reynolds less than 100 thousand.

link:https://www.sciencedirect.com/scienc...42727X19307593

yes. I did simulations 2D-steady with kwsst and k epsilon before. But I don't know about les and transient settings.

Would suggest to search in literature what LES parameters and what subgrid scale model they used for this kind of a problem previously, or for similar problems with lower Reynolds numbers.


This page also has a few useful references https://www.cfd-online.com/Wiki/Larg...imulation_(LES) if you find it needs more, they can be discussed here and added to the wiki.


Please let me know if you have further questions.
zagros135 likes this.
Светлана is offline   Reply With Quote

Old   May 18, 2022, 05:19
Default
  #5
Senior Member
 
alainislas's Avatar
 
Alain Islas
Join Date: Nov 2019
Location: Mexico
Posts: 142
Rep Power: 6
alainislas is on a distinguished road
According to the paper, they used the dynamic Smagorinsky sub-grid scale (SGS) model. If you wanna do something similar, these are important aspects to consider from this LES work:

(1) They used a 2.9M cells hexahedral grid. Hexa mesh is a must for serious LES.
(2) Note they set the CFL condition to CFL = 0.8. Time steps are in the order of 10^(-7) sec. CFL < 1 is also a must for LES.
(3) They initialized the flow with a RANS case, and ran the LES for 2 flow through times.
(4) They imposed synthetic turbulence at the inlet
(5) They assessed the LES quality through the LES index of quality, see (Celik et al. 2006) https://doi.org/10.1115/1.3059703

I'd suggest you to first go through the LES basic theory, read about the SGS models and its significance on the TKE and energy spectrum.



In addiiton, double check if your 2D simulation is candidate for LES. From what I know LES is intrinsically 3D, just as turbulence.
zagros135 likes this.
alainislas is offline   Reply With Quote

Reply

Tags
ansys, oscillating airfoil

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
Specifying BC for LES simulation of pollutant dispersion problem in environment jzuzul OpenFOAM Running, Solving & CFD 8 June 21, 2018 08:21
LES simulation - Not able to bring down M value of every cell below 0.1 shettysds STAR-CCM+ 1 February 7, 2018 20:39
synthetic turbulence condition for LES simulation raunakjung Main CFD Forum 1 October 13, 2016 04:21
How to make grid for LES simulation dinhanh Main CFD Forum 3 November 11, 2015 03:37
LES simulation of bluff body at Re(d)=1200 arash_nl FLUENT 0 June 1, 2009 14:16


All times are GMT -4. The time now is 20:16.