BC Problems/Confusions

Shazlan

Hi all,

I need to analyze a toiletbowl. The problem is in setting the boundary regions. The inlets, where the water is flushed into the bowl, is okay - at least, that's what I think. The outlet is located just after the siphon. The problem is on how to indicate the open area (where our butt is). I was thinking of using pressure BC, since it is subjected to atmospheric pressure and temperature, but pressure and outlet BC cannot co-exist. How do I 'tell' star-cd that the area, which consist of atmospheric air? or in other words, how do I go about approching this problem. I am assuming that toiletbowl is quite common that everybody knows the general geometry and concepts on how it works. Your help is highly appreciated!