CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

Advection schemes for LES

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

LinkBack Thread Tools Display Modes
Old   May 15, 2001, 17:35
Default Advection schemes for LES
Posts: n/a
Has anyone tried using positive advection schemes for scalar transport in LES. While use of positive schemes is somewhat imperative in reacting flow simulations, the truncation error in such schemes smoothes out any steep gradients in the scalar field. This is at odds with the requirement(s) in the LES that schemes should have minimal dissipation and dispersion.
  Reply With Quote

Old   May 16, 2001, 19:58
Default Re: Advection schemes for LES
John C. Chien
Posts: n/a
(1). You either get an oscillating solution, which might diverge later on, or eliminate it first so that you can continue on. (2). If there was an ideal algorithm, then people would not be using such scheme I guess.
  Reply With Quote

Old   May 17, 2001, 13:43
Default Re: Advection schemes for LES
Posts: n/a
There are schemes which retain sharpness of the fronts without the undershoots and overshoots and excessive damping. These are smart ways of removing unwanted behavior of the solution with minimal loss of accuracy.

Typically a monotone (upwind-type) scheme is used to predict the solution and then a corrector step (often called the anti-diffusion step) is used to remove the excessive diffusion caused by the monotone scheme (in the predictor). This works well for conserved scalar fields since the advection-diffusion equation is linear (for a given velocity field) and thus allows for this split predictor-corrector approach. I was just wondering if anyone has used these methods in LES of reacting flows.
  Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
time stepping schemes for compressible DNS/LES shyamdsundar Main CFD Forum 0 January 15, 2010 00:15
advection schemes HELP Ben Main CFD Forum 1 February 28, 2005 16:12
Energy Conservation Schemes! Science Seeker Main CFD Forum 0 May 21, 2001 03:31
TVD Schemes Matt Umbel Main CFD Forum 1 January 25, 2000 05:21
Higher-order bounded convection schemes for pure advection with discontinuity Anthony Main CFD Forum 3 June 13, 1999 02:36

All times are GMT -4. The time now is 03:04.