There're mean and fluctuating velocities,Reynolds stress budgets,but not turbulent kinetic energy.Should I simply square each fluctuating component and sum up them?

If you have 9 budgets for 9 reynolds stress components u can add the budgets for diagonal Re-stresses namely the (u^2) bar, (v^2)bar and (w^2)bar budgets and divide by 2 to get turbulent k.e. budget... sorry if it is not that simple...

But what I want is the distribution of k.

Oh!I'm sorry!It's rms velocities,not fluctuating velocities.So I can simply square each component and sum up them.

Hi,

k=(uu+vv+ww)/2

DNS-data commonly gives you the value of each Reynolds stress and hence you just adds the normal-components and divide by two. Check that you have the Reynolds stress (e.g. uu) and not the fluctuating velocity (e.g. u).

/Jonas

Ah!I got it.Thank you, Jonas!