[Jasper Z]

Dear Foamers,

I am struggling with the method of calculating resolved turbulent kinetic energy in LES. I have read a lot of threads and see that we can calculate TKE by: 0.5*(Uprime2Mean_XX+Uprime2Mean_YY+Uprime2Mean_ZZ) . But Uprime2Mean is calculated from: u-UMean, where UMean is time-averaged velocity. I know this should work with the statistically stationary flow. However, what if we have a nonstationary flow, like the figure below?

Shouldn't we get the Uprime2Mean by subtracting ensemble-averaged velocity from the instantaneous velocity? If we use UMean, the results will be totally different. Any ideas?

Kind Regards,
Jasper