difference plot: turbulent kinetic energy (URANS) vs. Reynolds Stresses (LES)

fabfi · November 21, 2017, 09:56

Hey,

I have two cases (same mesh/geometry): URANS and LES (WALE)

I want to directly compare the turbulent kinetic energy from URANS against the reynolds stresses u'u' (and same for v'v' and w'w') in CFX Post.

By using case comparison and the "Difference"-function I can only plot the same variables against each other.

Is there a way to compare two different sets of variables in case comparison mode?

P.s.: I only look at one timestep. No time averaging of LES data so far.

-Maxim- · November 21, 2017, 10:17

maybe write an expression (& turn into a variable) and plot that?

fabfi · November 21, 2017, 10:29

yes I just tried the following expression

Turbulence Kinetic Energy @Case:1 - Statistical Reynolds Stess uu@Case:2

When I try to compile it gives me an error: The following unrecognised names were referenced: Case:1, Case:2, Turbulence Kinetic Energy, Statistical Reynolds Stess uu

Do you see any errors in the formulation?

November 21, 2017, 09:56	difference plot: turbulent kinetic energy (URANS) vs. Reynolds Stresses (LES)	#1
fabfi New Member anon Join Date: Oct 2017 Posts: 10 Rep Power: 8	Hey, I have two cases (same mesh/geometry): URANS and LES (WALE) I want to directly compare the turbulent kinetic energy from URANS against the reynolds stresses u'u' (and same for v'v' and w'w') in CFX Post. By using case comparison and the "Difference"-function I can only plot the same variables against each other. Is there a way to compare two different sets of variables in case comparison mode? P.s.: I only look at one timestep. No time averaging of LES data so far.

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November 21, 2017, 10:17		#2
-Maxim- Senior Member Maxim Join Date: Aug 2015 Location: Germany Posts: 415 Rep Power: 12	maybe write an expression (& turn into a variable) and plot that?

November 21, 2017, 10:29		#3
fabfi New Member anon Join Date: Oct 2017 Posts: 10 Rep Power: 8	yes I just tried the following expression Turbulence Kinetic Energy @Case:1 - Statistical Reynolds Stess uu@Case:2 When I try to compile it gives me an error: The following unrecognised names were referenced: Case:1, Case:2, Turbulence Kinetic Energy, Statistical Reynolds Stess uu Do you see any errors in the formulation?