I want the time-averaged values of the velocity derivatives and the turbulent kinetic energy in order to calculate the time-averaged components of the turbulent Reynolds stress tensor. (I perform an URANS calculation) Do I have to programm it myself in an UDF, or are there other ways to obtain it?

Thanks

arent fluent RANS are time averaged Navier stokes equations

? i am confused

I am sure the values of a steady flow is time-averaging by default. I am not sure whether the values of a unsteady flow is time-averaging or not. If your case is a steady flow, you can acquire the velocity derivatives and turbulent kinetic energy directly from Fluent.