Turbulence closures
 

Hi,

Could anyone please explain briefly what are single-point and two-point turbulence closures and their differences? Why they are called so? Which category includes major two-equation turbulence models (k-e, k-omega)?

Thanks

Re: Turbulence closures
 

Let NS(u(x1,t1)) be the Navier Stokes equation relatives to the fluctuating velocity at spatial cordinat x1 and time t1 and and let [.] be the Reynolds Averaging operator.

[u_i(x2,t2)*NS(u_j(x1,t1))]+[u_j(x1,t1)*NS(u_j(x2,t2))] is the two points two times double correlation equations - see D.I.A. (Kraichnan)

Making t2=t1 gives two points double correlation equations - see E.D.Q.N.M. (Orszag)

Making x2=x1 gives one points double correlation equations - see R.S.M.

Makinge i=j (and sum over i) gives k equation - see k-eps models