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Accessing Reynolds stresses

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Hi,

I performed a turbulent flow simulation with the k-eps model and I would like to access the Reynolds stresses for post-processing. Do you know which is the variable containing them? I looked in the help and I wasn't able to find anything.

Best,

J

1 Reply Last Post 25 nov 2011, 12:00 GMT-5

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Posted: 1 decade ago 25 nov 2011, 12:00 GMT-5
Hi guys,

COMSOL support provided me the solution, please find it below.

------

The best way to obtain the Reynolds Stress Tensor is probably to take the
expression for the Total Stress Tensor components (spf.T_stressx,
spf.T_stressy and spf.Tstressz) and remove the
pressure and laminar viscosity. The Reynolds stress tensor component is
what remains. This approach works for the compressible version of the
interface. If compressibility is set to "Incompressible", then the term
"(2/3)*rho*k" has been absorbed into the pressure and has to be added with
correct sign to the diagonal stress tensor components.

Please refer to page 145 of the CFD Users Guide (v4.2a) for more details
and let us know if you have any further questions.

------


J
Hi guys, COMSOL support provided me the solution, please find it below. ------ The best way to obtain the Reynolds Stress Tensor is probably to take the expression for the Total Stress Tensor components (spf.T_stressx, spf.T_stressy and spf.Tstressz) and remove the pressure and laminar viscosity. The Reynolds stress tensor component is what remains. This approach works for the compressible version of the interface. If compressibility is set to "Incompressible", then the term "(2/3)*rho*k" has been absorbed into the pressure and has to be added with correct sign to the diagonal stress tensor components. Please refer to page 145 of the CFD Users Guide (v4.2a) for more details and let us know if you have any further questions. ------ J

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