[babri]

hello , I compute location of center of pressure of my geometry in ansys fluent , as you know the moments around this point should be zero because drag and lift forces are acting at this point , but when I compute the moments around center of pressure it is not zero or near zero! so how to find center of pressure ?
some contour of my geometry attached

[sbaffini]

This is a quite common engineering misconception.

https://en.wikipedia.org/wiki/Resultant_force

As explained in the "Torque-free resultant" section, not all system of forces have a so called "center of pressure".

The fact that Fluent computes it "in any case" is just marketing.