I am trying to solve a problem concering roll coating. This is 2 rotating cylinders whith different speeds. The two cylinders are in the same horizontal plane. They don't touch eachother, but are close together. On one cylinder there is a fluid. When the fluid goes through the gap, the point where the cylinders are closest to eachother, both cylinders take some of the fluid. Is it possible to calculate how thick the film is on each cylinder?? I have looked a month at this problem now. I think it can be done with the Navier-Stokes formulas, but they could be too difficult to calculate manualy. I know it abolutely has something to do with the speed of the cylinders, and probably the gap between them.