[raytracer]

I am solving for a flow past a cylinder in external flow in 2D using the icoFoam solver. It consists of a circle in a rectangular domain.

I'm using the following boundary conditions:
1. Left side of the rectangle is the inlet with fixedValue velocity and zeroGradient pressure.
2. Right side of the rectangle is the outlet with fixedValue pressure and zeroGradient velocity.
3. fixedValue for velocity and zeroGradient pressure at the surface of the cylinder.

I have the following doubts:
1. Are the above conditions I've used correct?
2. I don't know what conditions to use for the top and bottom sides of the rectangle. Should I treat them as outlets as well?
3. What would be the difference between specifying the walls of the cylinder as 'wall' or 'patch'? Does the difference come into play only in turbulence simulations?

Thanks for the help.