CFD Online Logo CFD Online URL
Home > Forums > CFX

Separated Regions of Centrifugal Impeller

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

LinkBack Thread Tools Display Modes
Old   February 27, 2010, 12:05
Default Separated Regions of Centrifugal Impeller
Join Date: Apr 2009
Location: Dresden
Posts: 33
Rep Power: 8
Suzzn is on a distinguished road
Hello people!

i`d like to compare different impeller-geometries by the size of their separated regions. I`ve already compared the massflow rate that goes backwards through the inlet and outlet of the impeller and also through the outlet of a vaneless diffuser downstream. I implemented this by creating velocity contours with only 3 levels and defining the range with the same size of velocity in +/- that the recirculating regions become visible. Now i would like to have another criteria for comparing separation. I tried to make a contour of the wall shear stress on the impeller blades. Wall shear stress should become zero at the point of separation and finally negative when there is backflow but as CFX calculates the stress by vectors there is no +/- change at all. So all I can do is plotting the streamwise velocity over the walls (with conservative data) and compare the regions of negative velocity. Does anybody has an idee how to involve the wall shear stress or how to make it change its algebraic sign? I use the SST-Model...

I would be very happy about a hint...
Suzzn is offline   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
simulation of centrifugal impeller Txema FLUENT 1 February 23, 2007 02:08
boundary condition impeller centrifugal pump mino2006 FLUENT 2 December 28, 2006 19:07
Centrifugal impeller modelling Rik FLUENT 1 October 27, 2005 06:43
Please help.BC for centrifugal impeller Shiju G.Thomas FLUENT 4 August 11, 2005 05:27
centrifugal compressor impeller with splitter blad deepesh nanda Main CFD Forum 2 October 18, 2004 11:13

All times are GMT -4. The time now is 00:55.