Incorrect Volume calc in Fluent
 

Guys

Does any one know the exact method used by Fluent to calculate their cell volumes. I have a pyramid which Fluent thinks is negative but it is very much positive. If I rotate the cell through 45 degrees about the x-axis and then reload into fluent, it thinks it is fine !!!

I heard that they use 1-point Gaussian Quadrature to do their calc, but I need more specifics to reproduce their values.

Thanks

Mark