[watttt]

Hi there,

I am currently trying to simulate a simple prolate ellipsoid (http://en.wikipedia.org/wiki/Ellipsoid) in a fluid flow. But I am currently having problems showing that the simulation is independent of the position of the outlet. I have set the outlet as an average static pressure of 0 and can see form a pressure plot on the sym plane that the pressure has stabilised behind the object. But whenever I lengthen/shorten the outlet the drag force (calculated using the force function) changes! To make matters worse it doesn’t even change in a pattern, the force just randomly jumps about by 10% both up and down. Has anyone ever seen this before? The mesh I am using is consistent between all runs and looks pretty reasonable. This makes me think its a problem with the force function? I could be wrong through. Its driving me nuts!

Thanks