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

Pressure work term in turbulent K.E. equation

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

LinkBack Thread Tools Display Modes
Old   March 8, 2011, 13:21
Default Pressure work term in turbulent K.E. equation
Senior Member
Join Date: Apr 2009
Posts: 118
Rep Power: 8
lost.identity is on a distinguished road

I've been stuck on this problem for a while. I'm carrying out turbulent flame calculations, therefore I use the compressible versions of the turbulent kinetic energy equation (see Wilcox book on CFD modelling for example).

The problem is that the flame is thin, which leads to large changes in flow properties across a small length. Hence, this leads a large pressure gradient across the flame. The pressure work term in the turbulent K.E equation is given by


There are further modelling involved for \overline{u''_i} but I want to focus on the pressure gradient term. When I have this large pressure gradient, the turbulent kinetic energy goes negative (unphysical) and my calculations diverge. Also this usually happens during the first iteration. I'm wondering if there are any remedies for such behaviour?

Making the gradient less steeper solves the problem, but my calculations need to have this large gradient. I've tried increasing the number of grid points considerably, which didn't help.

Additional information, I'm using the pressure-correction method of Patankar as the pressure solver.

Many thanks
lost.identity is offline   Reply With Quote


presssure work

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
Is it possible to use divergence in the source term of an scalar transport equation? jannnesss CFX 0 January 8, 2010 20:53
Does star cd takes reference pressure? monica CD-adapco 1 April 19, 2007 11:26
pressure poisson equation on staggerred grid chandra Main CFD Forum 9 May 5, 2005 06:01
Hydrostatic pressure in 2-phase flow modeling (CFX4.2) HB &DS CFX 0 January 9, 2000 14:19
Why FVM for high-Re flows? Zhong Lei Main CFD Forum 23 May 14, 1999 13:22

All times are GMT -4. The time now is 03:00.