CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Use custmer defined function to calculate Re

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

LinkBack Thread Tools Display Modes
Old   January 24, 2006, 07:14
Default Use custmer defined function to calculate Re
Posts: n/a
I used a pressure inlet and pressure outlet bc for inlet and outlet respectively in a 2d case, i want to use the simulated velocity at inlet to calculate the Reynolds number, so i use coustmer defined function panel, and I chose "select operand field function from (VELOCITY->Velocity Magnitude )*(GRID->Y coordinates)/(PROPERTIES->Molecular viscosity), this means U*D(pipe width)/viscosity, but the results seems not right. any one who konw how to do this? or anyother easier method? thanks you very much
  Reply With Quote

Old   January 24, 2006, 09:39
Default Re: Use custmer defined function to calculate Re
Posts: n/a
Try the following definition: Re = U*D*density/viscosity

I think you have mixed up dynamic and kinematic viscosity. In your equation "viscosity" represents the kinematic viscosity but Fluent provides the dynamic viscosity.

kinematic visc = dynamic visc / density
  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
Compile problem ivanyao OpenFOAM Running, Solving & CFD 1 October 12, 2012 09:31
Version 15 on Mac OS X gschaider OpenFOAM Installation 113 December 2, 2009 11:23
Error with Wmake skabilan OpenFOAM Installation 3 July 28, 2009 00:35
User defined function hari FLUENT 0 October 9, 2007 03:24
How to create an user defined function? Cagdas FLUENT 1 September 5, 2007 20:02

All times are GMT -4. The time now is 06:48.