Problem with streamlines in an axial turbine.

error404 · May 8, 2014, 10:58

Hey CFXlers,

i´ve got some problems with streamlines in CFX-Post. In the application is an interface with nonoverlapping surfaces. In the discription for GGI´s and nonoverlapping surfaces is written that CFX creates a "no slip wall". In the first pic you see an application where a wall have been createt by myself. In the second picture CFX has to create a wall, but the streamlines are going wrong. The big mesh is rotating and the small mesh is stationary.

1.jpg
2.jpg

Can anybody explaine what was happend?

Thx

ghorrocks · May 8, 2014, 19:16

Check which element faces have been determined to be part of the interface. It might have missed some in the interface region. Can you post an image of the mesh on the interface?

error404 · May 9, 2014, 05:47

This is only a test application for my application, an axial turbine. Cause there I´ve got the same problem. Maybe there is a problem with some default setting in CFX?

Pic 1. first side of the interface
Pic 2. second side of the interface

1.jpg
2.jpg

I think it looks normal. It´s frozen rotor.

Thank you!!

ghorrocks · May 9, 2014, 07:40

Is it well converged?

Have you plotted velocity in stn frame?

error404 · May 9, 2014, 07:45

Yes, it coverged well.

It doesen´t matter if I plot velocity or velority str frame. The solution looks the same.

ghorrocks · May 10, 2014, 09:14

Have you tried the "Alternate rotation model"?

error404 · May 14, 2014, 04:44

Yes,

it looks the same.

May 8, 2014, 10:58	Problem with streamlines in an axial turbine.	#1
error404 New Member Simon Join Date: Apr 2014 Location: Stuttgart, Germany Posts: 22 Rep Power: 12	Hey CFXlers, i´ve got some problems with streamlines in CFX-Post. In the application is an interface with nonoverlapping surfaces. In the discription for GGI´s and nonoverlapping surfaces is written that CFX creates a "no slip wall". In the first pic you see an application where a wall have been createt by myself. In the second picture CFX has to create a wall, but the streamlines are going wrong. The big mesh is rotating and the small mesh is stationary. 1.jpg 2.jpg Can anybody explaine what was happend? Thx

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Problem with torque output from a turbine simulation.	pa-dundas	FLUENT	5	July 17, 2022 06:27
CFD_screening problem for Francis Turbine Optimization	berk can	Fidelity CFD	3	February 22, 2014 13:08
Surface streamlines on axial flow fans	Jennifer	CFX	2	February 17, 2009 15:50
Test Cases for Axial Flow Turbine	shraman	Main CFD Forum	0	July 25, 2006 05:43

May 8, 2014, 19:16		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	Check which element faces have been determined to be part of the interface. It might have missed some in the interface region. Can you post an image of the mesh on the interface?

May 9, 2014, 05:47		#3
error404 New Member Simon Join Date: Apr 2014 Location: Stuttgart, Germany Posts: 22 Rep Power: 12	This is only a test application for my application, an axial turbine. Cause there I´ve got the same problem. Maybe there is a problem with some default setting in CFX? Pic 1. first side of the interface Pic 2. second side of the interface 1.jpg 2.jpg I think it looks normal. It´s frozen rotor. Thank you!!

May 9, 2014, 07:40		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	Is it well converged? Have you plotted velocity in stn frame?

May 9, 2014, 07:45		#5
error404 New Member Simon Join Date: Apr 2014 Location: Stuttgart, Germany Posts: 22 Rep Power: 12	Yes, it coverged well. It doesen´t matter if I plot velocity or velority str frame. The solution looks the same.

May 10, 2014, 09:14		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	Have you tried the "Alternate rotation model"?

May 14, 2014, 04:44		#7
error404 New Member Simon Join Date: Apr 2014 Location: Stuttgart, Germany Posts: 22 Rep Power: 12	Yes, it looks the same.