CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Pre-Processing

kOmegaSST wall functions and mass inlet boundary

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

LinkBack Thread Tools Search this Thread Display Modes
Old   February 4, 2015, 05:58
Default kOmegaSST wall functions and mass inlet boundary
New Member
Frans Visscher
Join Date: Dec 2014
Posts: 2
Rep Power: 0
FransVisscher is on a distinguished road
Dear CFD'ers,

For my master Thesis I have to model an semi-confined jet, starting from the flat plate to and later on extend the model to an bend and multiphase. However I am currently struggling with the kOmega (SST in particular) I have noticed the following things:

The automatic wall functions for the kOmegaSST is calculating the dissipation omega as
w = sqrt((w_vis)^2+(w_log)^2)
which are given in Menter's publications. I found this verification in the wall function source code (the only one available in OF 2.3.x for omega for incompressible flow). So assume the wall function must be specified separately.

The source code for the turbulence model however also indicates that it uses the modification by Hellsten to account for rough walls using the extra blending factor F3. Now here comes my first problem: why is the omega wall function than not equipped with the rough wall condition given i believe at first in Wilcox's paper as:
where u_tau is the friction velocity, nu is kinematic viscosity and S_R is a factor dependent on the non dimensional equivalent grain size?

Secondly, how can I specify the mass injection boundary condition for omega at my inlet as suggested also by Wilcox:
where S_B is a factor depending on the normal velocity at this surface in a non dimensional form defined as v_n+=v_n/u_tau

Note: w stands here for omega

Now of course I can start coding myself but that would take me more time than I probably have for this 'introduction problem' and it will astonish me when these functions are never been missed before in OF by others (if they really are not part of it). So does anyone have an answer?

Thanks in advance!

Last edited by FransVisscher; February 4, 2015 at 07:01.
FransVisscher is offline   Reply With Quote


boundary, komegasst, menter, omega, wilcos

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
Wind turbine simulation Saturn CFX 58 July 3, 2020 01:13
Question about heat transfer coefficient setting for CFX Anna Tian CFX 1 June 16, 2013 06:28
An error has occurred in cfx5solve: volo87 CFX 5 June 14, 2013 17:44
Error finding variable "THERMX" sunilpatil CFX 8 April 26, 2013 07:00
Water subcooled boiling Attesz CFX 7 January 5, 2013 03:32

All times are GMT -4. The time now is 21:51.