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Huge Heat Transfer Coefficient with SST turbulence model

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Old   September 14, 2009, 04:13
Default Huge Heat Transfer Coefficient with SST turbulence model
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Andi
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Hello!

I am modelling conjugate heat transfer at a pipe - the pipe is cooled by air, which flows through the pipe. Therefor I use the SST turbulence model. The y+ value is y+ <1 (around 0.5) The number of nodes in the boundary layer is about 15. The value for the wall heat transfer coefficient which i got from the simulation is very high with 26105,7 W/mK (From analytical calculations I got a value around 650 W/mK)

Does someone know what the reason could be?

Thank you in advance,
Andy
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Old   September 14, 2009, 05:10
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try to check reference temperature for calculation of HTC
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Old   September 15, 2009, 09:23
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The temperatures are ok. I did the simulation also with the k epsilon turbulence model (with scaleable wall functions) and then I got much better results than with the sst model. So I dont understand why the results with use of the sst turbulence modell are so high.
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Old   September 15, 2009, 18:29
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I don't think you have understood denizen's point. HTC is by default referenced to a local temperature which is another variable available for viewing in CFD-Post called "Wall Adjacent Temperature". This variable is often miles away from the reference temperature an engineer would use in the bulk flow.
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Old   January 9, 2010, 08:40
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Thank you! This was very helpful!
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