Emergency help Frozen rotor connection

Mehdi534 · August 31, 2012, 05:21

Hello all,
I'm simulating one passage of turbine + 360 degree diffuser in a model. I would like to use frozen rotor connection between blade outlet and diffuser inlet. My problem is that when I put pitch ratio (it is 63), cfx just stretching the one passage data over diffuser inlet surface and doesn't copy the inlet data 63 time over diffuser surface. I need a emergency help on this issue, please let me know if some body has an idea to solve the problem.Thanks in advance.

D.B · August 31, 2012, 06:00

Hi,
First what is the need of a full 360 degree model of diffuser if you are using only a sector of rotor, since if flow is axisymmetric in rotor it should be in diffuser, if its not in diffuser it shouldn't be in rotor. Other I dont know how it has to be done.

ghorrocks · August 31, 2012, 07:02

Are you sure your pitch ratio is correct? Rather than 63 have you tried 1/63?

Mehdi534 · August 31, 2012, 07:04

Hello, Thanks for the response, there are some sturts in diffuser and flow in the diffuser in not axisymmetric, in addition exit flow in turbine passage is not axisymetric, I know what you mean, but I can not model all the turbine passages becasue my model will be so heavy and by this way I will have a inlet profile very close to diffuser inlet.

Mehdi534 · August 31, 2012, 07:06

I put 63 for the pitch, I haven't used 1/63, but I can try with that too,

Mehdi534 · August 31, 2012, 08:03

I tried with 1/63 but it has the same problem, I also tried automatic pitch change but it doesn't work.

August 31, 2012, 05:21	Emergency help Frozen rotor connection	#1
Mehdi534 New Member Mehdi Bahador Join Date: Oct 2011 Posts: 10 Rep Power: 14	Hello all, I'm simulating one passage of turbine + 360 degree diffuser in a model. I would like to use frozen rotor connection between blade outlet and diffuser inlet. My problem is that when I put pitch ratio (it is 63), cfx just stretching the one passage data over diffuser inlet surface and doesn't copy the inlet data 63 time over diffuser surface. I need a emergency help on this issue, please let me know if some body has an idea to solve the problem.Thanks in advance.

August 31, 2012, 06:00		#2
D.B Member DB Join Date: Apr 2011 Posts: 87 Rep Power: 15	Hi, First what is the need of a full 360 degree model of diffuser if you are using only a sector of rotor, since if flow is axisymmetric in rotor it should be in diffuser, if its not in diffuser it shouldn't be in rotor. Other I dont know how it has to be done. __________________ -D.B

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August 31, 2012, 07:02		#3
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Are you sure your pitch ratio is correct? Rather than 63 have you tried 1/63?

August 31, 2012, 07:04		#4
Mehdi534 New Member Mehdi Bahador Join Date: Oct 2011 Posts: 10 Rep Power: 14	Hello, Thanks for the response, there are some sturts in diffuser and flow in the diffuser in not axisymmetric, in addition exit flow in turbine passage is not axisymetric, I know what you mean, but I can not model all the turbine passages becasue my model will be so heavy and by this way I will have a inlet profile very close to diffuser inlet.

August 31, 2012, 07:06		#5
Mehdi534 New Member Mehdi Bahador Join Date: Oct 2011 Posts: 10 Rep Power: 14	I put 63 for the pitch, I haven't used 1/63, but I can try with that too,

August 31, 2012, 08:03		#6
Mehdi534 New Member Mehdi Bahador Join Date: Oct 2011 Posts: 10 Rep Power: 14	I tried with 1/63 but it has the same problem, I also tried automatic pitch change but it doesn't work.