CFD Online Logo CFD Online URL
Home > Forums > OpenFOAM Programming & Development

Static vs dynamic pressure in Reynolds stress source term

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

LinkBack Thread Tools Display Modes
Old   August 13, 2010, 14:45
Default Static vs dynamic pressure in Reynolds stress source term
New Member
Nat Trask
Join Date: Mar 2009
Location: Providence, RI
Posts: 18
Rep Power: 8
natrask is on a distinguished road
My understanding of the divDevRhoReff function in the turbulence models is that it returns the deviatoric part of the Reynolds stresses, and that when the pressure equation is solved in the following part of the loop the contribution of the 2/3*rho*k term is lumped into the pressure in the momentum equation. Therefore, to get the static pressure, it's necessary to substract off the contribution of the turbulence.

However, when you look at the equations of state that are being used in many of the solvers, they are using the incorrect pressure (p = pstatic + 2/3*rho*k) to calculate the density. For strictly single phase flows, the difference is negligible, but for turbulent flows involving mixtures of liquid and gas this can make a significant difference in the resulting pressure.

Has anyone else given some thought to this situation? It seems that the majority of solvers in OpenFOAM use the same assumption, and I want to make sure that I'm not missing something.

natrask is offline   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
problematic source term in UDS ak6g08 Fluent UDF and Scheme Programming 6 February 10, 2015 01:19
Version 15 on Mac OS X gschaider OpenFOAM Installation 120 December 2, 2009 11:23
gradient source term UDF ak6g08 Fluent UDF and Scheme Programming 0 July 9, 2009 06:37
Pressure jump and momentum source Tanya FLUENT 1 June 4, 2009 15:22
UDF Source Term Units? Brian FLUENT 1 October 24, 2005 09:15

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