CFD Online Logo CFD Online URL
Home > Forums > OpenFOAM Running, Solving & CFD

Low pressure result in low velocity region for RNG-ke?

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

LinkBack Thread Tools Display Modes
Old   July 14, 2011, 20:48
Default Low pressure result in low velocity region for RNG-ke?
New Member
Join Date: Apr 2011
Posts: 6
Rep Power: 8
Gabbee90 is on a distinguished road
I have ran a SimpleFOAM RAS -RNG- K-e model of a ball vale at a small % opening position, as an axi symmetric model.
At the moment I have using PCG with a preconditioner of GAMG for the pressure calculations in fv schemes:
solver PCG;
preconditioner GAMG;
tolerance 1e-7;
relTol 0.1;
smoother GaussSeidel;
nPreSweeps 0;
nPostSweeps 2;
cacheAgglomeration on;
agglomerator faceAreaPair;
nCellsInCoarsestLevel 10;
mergeLevels 1;
tolerance 1e-06;
relTol 0.01;
maxIter 100;

solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0.1;

for K U and epsilon

My relaxation factors are:
p 0.7;
U 0.2;
k 0.5;
epsilon 0.5;

My result has an extremely low pressure region in area of low velocity. I feel as though this is not correct and am not sure what to do to optimize the model and get a better result. I have tried adjusting delta T and write time in controldict. I can get pressure residuals to converge but still have the same result
Any Ideas?
Gabbee90 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
Calculation of the Governing Equations Mihail CFX 7 September 7, 2014 06:27
Is Fluent applicable to simulate velocity distribution under low pressure (~100pa)? beastieboys FLUENT 0 March 3, 2010 02:55
Initializing the pressure in a region Manish Mehta FLUENT 0 July 16, 2006 12:26
Multicomponent fluid Andrea CFX 2 October 11, 2004 05:12
regarding low pressure handling subodh kumar Main CFD Forum 1 November 20, 1999 23:23

All times are GMT -4. The time now is 02:06.