[dennis722]

Originally Posted by me3840

Just because the total integrated force should be zero doesn't mean the local effects of momentum in the 3rd dimension are irrelevant.

can i find this written somewhere in a book? because thats for my bachelor thesis. I didnt find something in the star ccm+ handbook..

[me3840]

Originally Posted by dennis722

can i find this written somewhere in a book? because thats for my bachelor thesis. I didnt find something in the star ccm+ handbook..

This is pretty simple mathematics..

A function f(x) has integral F=0. Because F=0, does this demand that f=0 everywhere? No, obviously, half of f could be -1 and the other half 1, or an infinite number of other possibilities.

It would be a good idea to discuss this subject with your professor.