Can someone pls give me instructions as how to solve turbulent mixing problem. I am given intial condition of Mach # of 2.0 and 3.0 above and below a plate. I have to model this in gambit and then solve using fluent. Can anybody provide me with some help.. Its urgent Thanks

So you're looking at a spatially developing mixing layer, at supersonic speeds? What kind of models are you going to be using in the flow solution, and what type of geometry will your mesh be based on?

I have created a rectangular mesh of 120*100 grid size. top and bottom surface are symmetrical, inlet has two streams conditons I will be using standard k-epsilon model and rng k-epsilon model and then compare the result with analytical solution. I have created the mesh in gambit, but I do not know how to setup the problem in fluent. I mean how to generate contour of mixing layer.

One can use a hyperbolic tangent function to specify the inflow condition for the layer, of the form

u(y) = 0.5(U1 - U2) + 0.5(U1 + U2)tanh(di/2)

where U1 and U2 are the freestream velocities of the high- and low-speed streams, and di is the initial vorticity thickness of the layer.

A RANS type solution may give reasonable results when compared to an analytical solution, but it will be unable to resolve the large-scale coherent strucutres known to be present in the shear layer flow at both subsonic and supersonic velocities.