Reynolds stresses LES
 

Suppose I do an (2D unsteady) LES-simulation, and I want yo calculate the Mean (averaged over all timesteps in unsteady calculation) Reynolds stresses uu, uv, vv from the turbulent kinetic energy k and the velocity derivatives. How do I obtain Mean values of k and velocity derivatives over all time-steps? Do I have to programm a routine myself in an UDF?

Thanks