Hello everyone,

I am looking for a closed formula equation to analytically compute the windage (others call them churning) losses in the gap between two disks, displaced by a certain distance, one stationary and the other rotating at a given speed.

For e-motor designers, this is the case of an axial flux machine, for example, but I believe it is a rather general question that can have strong similarities in many other fields.

Thanks a lot for your help.