Stratified flow simulation in Strarccm+
 

I want to use strarccm+ to simulate the three-layer fluid, one is the air, the other two are freshwater and seawater. I want to know how to set up the basic parameters of the software to achieve this simulation.

Your question is too broad and will not get a good response. It's a bit like asking "I've never driven a car before, can you tell me how to drive?"

Go through some of the multiphase tutorials and start thinking about your simulation, then come back and ask more specific questions for help.

Maybe I did not state the question clearly.
I have realized the continuously stratified flows simulation based on introduce 'Energy Equations' (Temperature) to control the Density. Just like set up the density as a function of temperature and the temperature as a function of depth.
Like ρ= ρ（T）, T=T(h), then ρ=ρ（T(h)）; If I use this method, I can simulate the continuous stratified flow based on the function.

But now I want to simulate the strong stratification of water which means the water is separate into only two parts, the salt water and the fresh water. In this case, introducing the 'Temperature' to control the density will have some problems.
So I want to use the VOF model to realize the simulation. However, I try set up the volume fraction as a function of depth, it doesn't work. There were not stratification phenomenon any more. I don't know where the problem is.

Here are the details of the setting:
First, set up three volumes, the air, fresh water and salt water. ρ(fresh water)=998kg/m³，ρ(sea water)=1025kg/m³;
Then, set up the volume fraction as a function of depth; However, when I initial the flow field, the stratified flow can not be realized. there only exist two layers, one is the air the other is the uniform density water.
So I want to know whether there are some mistakes in the setting.