[Michael.J]

Hi,

I am simulating heat transfer between solid body in fluid environment with phase chage of the fluid, so there are 2 phases defined in fluid domain with thermal phase change. What is important for me are "wall heat flux" and "heat transfer coefficient". In ANSYS CFX 12.0 I used to create monitors of heat flux value by monitoring expression:

areAve(Wall Heat Flux)@REGION:contact_solid for example

Everything used to work very nice until i updated to 12.1 this week. Now monitor for wall heat flux show me constant value of 0. And since htc cant be used for monitoring directly i used to create expression for:

htc=Wall Heat Flux/(temp difference betwen suface and fluid)

and now i cant get any reasonable value.

Anyone has some ideas on what's wrong? I tried everything started whole setup from sratch etc. and form old ccl's and still nothing.

If there is some other way to get htc from cfx results i'd be glad to know

Regards

[ghorrocks]

The HTC is in the results file. Press the "...." button to see the additional variables. The variable you are looking for is "Wall Heat Transfer Coefficient". Be careful of the reference temperature used for the HTC.

I have no idea why V12.1 broke the calculation. Seems strange. Have a look in the release notes and if you can't see an explanation for the behaviour report it to your CFX support person as a bug.

[Michael.J]

Thx i'll report it if i wont come up with solution. I don't have any specified constant temperatures on any wall so the reference temperature for htc wont be a problem.

[mvoss]

hey,
afaik this is an reported bug in 12.1 and will be fixed if you update/patch your WB. Ask your cfx-support.

neewbie

[Michael.J]

Thx great to know that the problem doesn't lie on my side.

Regards