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VG March 19, 2008 01:40

Range of Y+ for two-layer approach in CCM+
 
Hi What should be the control range for y+ when using realizable k-epsilon turbulence model with two-layer all y+ approach. I have a mesh in which y+ is varying from 0.001 to 50 while using above mentioned model.Can this model accomodate this range of y+ as its name suggesses (all y+) or y+ must be controlled below 1 like in Low-Reynolds number approach. Thanks in Advance.

Achim Frahm March 25, 2008 15:29

Re: Range of Y+ for two-layer approach in CCM+
 
What is your aim? Correct pressure loss or heat transfer?

Theoreticaly y+ should not be in a range between 10-25.

To check it I would compare the results of two different calculations. One with a finer (y+=0.1-3) and one with a coarser mesh (y+=30-50). When the differences in results are small enough when it is ok.

Another possibility: make the mesh finer in areas with y+>5 with volume sources.

Achim



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