Hi everybody,
I need to find out the turbulent Prandtl number in KPP mixing scheme, I checked the code, and I found these lines;
!For eddy viscosity
Kv(i,j,k)=lmd_iwm + lmd_nu0m*nu_sx + lmd_nu0c*nu_sxc
!For eddy diffusivity
Kt(i,j,k)=lmd_iws + lmd_nu0s*nu_sx + lmd_nu0c*nu_sxc
The first terms (i.e. lmd_iwm and lmd_iws) are for internal waves and they are relatively small (order of 10^-6).
My question is;
If I got a overflow problem in which I know the most of the mixing occurs from shear instability, no convection or no double diffusion and since lmd_nu0m and lmd_nu0s are equal to each other (=10^-4), can I say turbulent Prandtl number (Pr_t) is approximately 1. I guess Pr_t should be;
Pr_t=Kv/Kt =~ lmd_nu0m*nu_sx/lmd_nu0s*nu_sx = lmd_nu0m/lmd_nu0s =1.
I am opened any suggestions or comments, and I know this doesn't sound exactly as the Pr_t from Large et al.