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

boundary conditions for turbulence model

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

LinkBack Thread Tools Display Modes
Old   February 5, 2016, 05:34
Default boundary conditions for turbulence model
Join Date: May 2014
Posts: 50
Rep Power: 5
Yage is on a distinguished road
Dear All,

I would like to know the boundary conditions for k-omega model.

1. is there any scalable wall function in OpenFOAM?

My y+ values vary from 1 to 10.

According to the guidance

For 1<y+<300, use kqRWall and omegaWall function, and k wall value is set to be 0 and omega wall is set to be 10x6xnu/(0.075y^2)=51200 for my case.

The internalfield and other boundaries for k=3/2(UI)^2=0.04
and omega=(rho.k/mu).(mut/mu)^(-1)=400

Please help me check if these boundary conditions are reasonable.
And this is a problem: the k value at wall will change to 0.04 (internalfield value) after decompose to avoid crash. (OpenFOAM 2.3.0). and due to my experience, all other non-zero k wall value will also change to internalfield value, which confused me.

2. I further refined my mesh to y+=1~2 so that I dont need wall function, then which boundary condition should I use?

I tried fixedValue with 1e-10, but the simulation got a bounding k issue after several timestep and the pressure force on wall is extremely high. I used celllimited linear upwind for k and omega

So I have no idea how to solve this problem

Thanks in advance for your suggestion.

Yage 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
sliding mesh problem in CFX Saima CFX 45 September 22, 2015 10:53
Problem with SIMPLEC-like finite volume channel flow boundary conditions ghobold Main CFD Forum 3 June 15, 2015 11:14
Question about heat transfer coefficient setting for CFX Anna Tian CFX 1 June 16, 2013 06:28
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 05:05
Water vapour condensation in CFX-5.7.1 hdj CFX 1 November 27, 2005 08:15

All times are GMT -4. The time now is 04:30.