Pls...Any help in computing velocity gradients

saranyasimi · December 4, 2009, 23:26

hi frnds...........I am a beginner in UDF programming.Can anyone help me out of this problem.........I would like to give the boundary condition at the inlet as : u velocity gradient in the x direction=0; v velocity gradient in the y direction=0;

I tried out many programs.Even though the programs had been sucessfully interpreted,each time i recieve an error signal :Fluent received a fatal signal...........Acess vioalation error.

Can anyone help me on this.......i would be grateful if i get any sample program concerning this problem

dmoroian · December 11, 2009, 04:57

Fluent needs the velocity values (Dirichlet type of BC, not Neuman), so if you want to specify the gradients, you will have to extract from them the actual value of the velocity.
In any case it would help if you post the udf code.

Dragos

dashingd · December 11, 2009, 05:08

............

saranyasimi · December 12, 2009, 08:31

Hey thanx............I will just post my code in two days............Hope u will help me out

December 4, 2009, 23:26	Pls...Any help in computing velocity gradients	#1
saranyasimi New Member Join Date: Dec 2009 Posts: 6 Rep Power: 16	hi frnds...........I am a beginner in UDF programming.Can anyone help me out of this problem.........I would like to give the boundary condition at the inlet as : u velocity gradient in the x direction=0; v velocity gradient in the y direction=0; I tried out many programs.Even though the programs had been sucessfully interpreted,each time i recieve an error signal :Fluent received a fatal signal...........Acess vioalation error. Can anyone help me on this.......i would be grateful if i get any sample program concerning this problem

December 11, 2009, 04:57		#2
dmoroian Senior Member Dragos Join Date: Mar 2009 Posts: 648 Rep Power: 20	Fluent needs the velocity values (Dirichlet type of BC, not Neuman), so if you want to specify the gradients, you will have to extract from them the actual value of the velocity. In any case it would help if you post the udf code. Dragos Last edited by dmoroian; December 12, 2009 at 02:22.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
UDF velocity and temperature	Raj	FLUENT	3	February 1, 2009 18:29
calculate the average velocity of particles	robert	FLUENT	0	August 1, 2008 09:44
How to calculate Velocity?	Kali Sanjay	Phoenics	1	May 1, 2006 13:57
Neumann pressure BC and velocity field	Antech	Main CFD Forum	0	April 25, 2006 02:15
Velocity Gradients at Inviscid Flow	Lada	FLUENT	0	January 15, 2001 07:20

December 11, 2009, 05:08		#3
dashingd New Member d Join Date: Dec 2009 Posts: 1 Rep Power: 0	............

December 12, 2009, 08:31		#4
saranyasimi New Member Join Date: Dec 2009 Posts: 6 Rep Power: 16	Hey thanx............I will just post my code in two days............Hope u will help me out