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Old   February 11, 2006, 01:18
Default INTERFACES
  #1
Badrinath
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Hi, I have a doubt regarding the interfaces. The interfaces for each domain has to have the sme variables values (pressure,Total pressure, velocity etc.) But when I have did the analysis for a simple rotating domain which has frozen rotor interface it is giving diffrent values for the each domain interface. why it is so?

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Old   February 12, 2006, 23:38
Default Re: INTERFACES
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Opaque
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Dear Badrinath,

At intefaces, the solution variables (velocity for momemtum, pressure for continuity, enthalpy for energy) should be the same at the intefaces..

Other variables such as total pressure, total temperature may not be the same... Also, are you looking at hybrid values or conservative values?

Good luck, Opaque..

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Old   February 13, 2006, 07:30
Default Re: INTERFACES
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Ram
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Badrinath

I am also doing stn and rotating domain models, I did use the interfaces and found the various variables to be close. What exactly r u looking for ?

Ram
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Old   February 13, 2006, 22:17
Default Re: INTERFACES
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badrinath
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Dear Opaque, I am looking at the conservative values only but as per the theory the interfaces has to have the same values why it is changing is there any reason for this. What ever you told is correct total pressure and the total temperature is varying why it is so as interface means it is same. IS there any command in CFX where we can fuse the interfaces so that it can be a single face. In this I think we can reduce the computational domain also if I am not wrong.

wih regards Badrinath
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Old   February 14, 2006, 10:21
Default Re: INTERFACES
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opaque
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Dear Badrinath,

Are your interface meshes 1:1, and both sides of the interfaces on the same frame? if yes, you can try to set them up as translational periodicity and do not use the general grid interface (GGI) approach.. Otherwise, there is only the GGI option.

I do not recall where the GGI approach guarantee that the conservative values are the same on both sides of the interface.. It is a vertex based model and the conservative value represents the mean value of control volume on a given side..The finer the mesh is normal to the interface, the closer the values, but never the same..

Perhaps it is something else wrong.. Have you contacted your CFX help desk..They should know what is happening

Good luck, Opaque

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