spray computation with LES

Stefan

Here is another one:

I am doing LES calculations of spray/ wall impingement. My domin is of cylindrical shape with a butterfly mesh inside. At first I was using a wall BC at the bottom (obviously) and pressure BC's elsewhere. This gave me reasonable results at the beginning of the computation but at a later stage I got wave-like fluctuations at the upper pressure BC. I was able to fix this by changing the upper pressure BC also to a wall BC. Now, the fluctuations are gone but I get some source/ sink-like spots in my domain. Has anyone an idea what mistake I am doing here ?