# custom pressure field at the faces

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

April 3, 2009, 08:09
custom pressure field at the faces
#1
New Member

souviktor
Join Date: Mar 2009
Posts: 11
Rep Power: 10
Hi,
I am simulating a configuration with high non linear body force using udf.Obviously fluent stores this body force at the cell center.So during calculation of velocity if the body force is needed at the cell face it has to interpolate by whatever scheme.But the body force is so nonlinear that it incorporates large error.
I have hand written code that solves this issue by adding a part of body force(the highly non linear part which varies only spatially) to the pressure and defining pressure and velocity in a staggered way.there I have two types of cells ,scalar and vector.scalars(pressure ,density,temperature) are defined at the scalar cell center and vectors(velocity)are defined at the vector cell center.the face of a scalar cell is center of the vector cell.(please see the attachment)

So essentially I define pressure (with a part of body force added to it) at the scalar cell center and velocity is computed by using pressure at its two faces.

Fluent on the contrary uses collocated scheme which means defining pressure and velocity at the same point.

In fluent how can I at all achieve this?can I use define_adjust udf to manually set the pressure prior to each iteration?

any suggestion is greatly appreciated ..please pardon me if I am making any fundamental mistake in understanding and describing the situation!
Attached Files
 grid.doc (42.0 KB, 7 views)

 Tags face, pressure, staggering

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post paka OpenFOAM 15 July 21, 2008 05:03 matteo_gautero OpenFOAM Running, Solving & CFD 0 February 28, 2008 07:51 zoune OpenFOAM Running, Solving & CFD 20 February 4, 2008 19:42 qunwuhe@hotmail.com Main CFD Forum 4 October 14, 2007 07:38 George Gardner FLUENT 0 October 12, 2007 08:00

All times are GMT -4. The time now is 13:43.