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

k-e equation in in cartesian coords

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

LinkBack Thread Tools Display Modes
Old   January 15, 2003, 19:46
Default k-e equation in in cartesian coords
Posts: n/a

I'm trying to expand the k-epsilon equations from cartesian tensor notation to cartesian coordinates to form a system of equations for finite element analysis.

Both the k- and e-equations contain a term with the Reynolds stresses expressed as follows:

( @Ui/@Xj + @Uj/@Xi ) ( @Ui/@Xj)

Does this represent a scalar quantity (ie the scalar product of the two tensors), or a 3x3 matrix product in 3D?

Thanks in advance, -CS
  Reply With Quote

Old   January 15, 2003, 22:45
Default Re: k-e equation in in cartesian coords
Linfeng BI
Posts: n/a
Any term in k and e equations is scalar because k and e themselves are scalars.
  Reply With Quote

Old   January 20, 2003, 09:45
Default Re: k-e equation in in cartesian coords
Posts: n/a
What you are looking at is part of the production term in k and eps-equation, which are - yes a scalar. However in order to compute the production term you need to cycle through i and j indices from 1 to 3, hence the expression becomes something like:


  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
Calculation of the Governing Equations Mihail CFX 7 September 7, 2014 06:27
Constant velocity of the material Sas CFX 15 July 13, 2010 08:56
Viscosity and the Energy Equation Rich Main CFD Forum 0 December 16, 2009 15:01
mass flow in is not equal to mass flow out saii CFX 2 September 18, 2009 08:07
Two-Phase Buoyant Flow Issue Miguel Baritto CFX 4 August 31, 2006 12:02

All times are GMT -4. The time now is 03:57.