Velocity within symmetry plane..JOB DEPENDS ON ANSWER!

prikeyma · September 8, 2010, 11:36

Hello,

I simulated flow through a circular half pipe using Fluent. I defined a symmetry plane in order to save computation time. When I exported the simulation results and load the exported files into Tecplot all of the velocities within the plane are reported as zero which is incorrect. I understand that the velocity components normal to the symmetry plane should be zero but the velocity within the plane should not be zero.

Has anyone encountered this problem or have any idea why the velocities are zero??

My graduate student position depends on the answer to this question

.I maybe kicked out if I don't solve this soon.

-Keyma

stuart23 · September 9, 2010, 05:12

Check the wall shear on the surface. The wall shear should be 0 (ie free slip). If it is not zero, you may have set your boco wrong.

applemango · September 9, 2010, 08:38

I dont really think that if u r computing a closed circular pipe you can do it as the way u have done, that is defining symmetry plane.
Y dont u try using anxisymmetric option? That is create a rectangle with depth=1/2 the diameter and define that as axis and when u open it in fluent just click on the anxisymmetric option in the solver.
Hope this helps you.

Varad..

prikeyma · September 10, 2010, 11:52

Thanks for the replies. I really appreciate your help.

@stuart23: I checked the wall shear and Tecplot list all the values as "N/A" rather than 0.

@applemango: Can you explain why you believe the symmetry plane method would not work for the simulation of unsteady flow through a circular pipe? In the region of the pipe that excludes the symmetry plane, the velocity data appears very reasonable. So I think the simulation has been run correctly but I don't know how to get Tecplot to read the velocity data at the symmetry plane correctly.

September 8, 2010, 11:36	Velocity within symmetry plane..JOB DEPENDS ON ANSWER!	#1
prikeyma New Member Keyma Join Date: Aug 2010 Posts: 16 Rep Power: 16	Hello, I simulated flow through a circular half pipe using Fluent. I defined a symmetry plane in order to save computation time. When I exported the simulation results and load the exported files into Tecplot all of the velocities within the plane are reported as zero which is incorrect. I understand that the velocity components normal to the symmetry plane should be zero but the velocity within the plane should not be zero. Has anyone encountered this problem or have any idea why the velocities are zero?? My graduate student position depends on the answer to this question .I maybe kicked out if I don't solve this soon. -Keyma

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September 9, 2010, 05:12		#2
stuart23 Senior Member Stuart Buckingham Join Date: May 2010 Location: United Kingdom Posts: 267 Rep Power: 26	Check the wall shear on the surface. The wall shear should be 0 (ie free slip). If it is not zero, you may have set your boco wrong.

September 9, 2010, 08:38		#3
applemango New Member Join Date: Mar 2010 Posts: 14 Rep Power: 16	I dont really think that if u r computing a closed circular pipe you can do it as the way u have done, that is defining symmetry plane. Y dont u try using anxisymmetric option? That is create a rectangle with depth=1/2 the diameter and define that as axis and when u open it in fluent just click on the anxisymmetric option in the solver. Hope this helps you. Varad..

September 10, 2010, 11:52		#4
prikeyma New Member Keyma Join Date: Aug 2010 Posts: 16 Rep Power: 16	Thanks for the replies. I really appreciate your help. @stuart23: I checked the wall shear and Tecplot list all the values as "N/A" rather than 0. @applemango: Can you explain why you believe the symmetry plane method would not work for the simulation of unsteady flow through a circular pipe? In the region of the pipe that excludes the symmetry plane, the velocity data appears very reasonable. So I think the simulation has been run correctly but I don't know how to get Tecplot to read the velocity data at the symmetry plane correctly.