Problem: swimming pool water surface motion simulation

How to model swimming pool is filled with water and above the water surface, there will be a boundary layer type wind.

I'm considering 2D simulation. How can I define one surface with water and the other surface with air as the initial condition?

Use VOF and patch regions appropriately.

Thank you, Jack.

Well, this is a classic Fluid Dynamics Problem - you can do an estimate using hand calculations. Refer to Fluid Dynamics by White.

The solution for the fluid direction vector as a function of depth ends up being a spiral (as seen from the top), if I remember correctly. So if you do a 2D simulation, this will be a shear driver flow only - which I suspect will not give the correct answer.

Thank you for your advice, Riaan.

When I posted my first question, I didn't know how to fill water in the swimming pool as an initial condition. That is, just nothing else than, to patch the area with water from the 'Initialize-patch' (my problem was 2-phase flow (liquid water as pahse 2 and air as phase 1).

My objective from the simplified, 2D simulation was what is the minimum wind speed separating water bubbles from the water surface.

The main purpose was what will be the wind speed that separates water from a surface. The water was falling along the surface and it will be detached from the surface when wind speed increases.

Full, 3D simulation of the problem was so complicated and was not converged when I employed VOF model. We compromised and simplified the problem and got an engineering solution. We will probably pubulish the results in a conference at first and then a journal paper. This problem can not be solved in a wind tunnel test. Only CFD is the solution.