On the basis of gear shaping generation theory

the equation of the spur face gear is deduced

the computational fluid dynamic model（CFD） of single phase（such as the air） in the gearbox after meshing is established by the finite volume method（FVM）

and the numerical analysis of turbulence model is carried out by the CFD technology.The new method of calculation the windage power loss（WPL） of the face gear is put forward.In order to reduced the WPL

the WPL and pressure distribution of the un-shrouded model with the shrouded model are compared.The result shows that the increase ratio of WPL is obviously increased with the speed of face gear.Through the comparison on the calculation result of un-shrouded and shrouded

the result shows that the WPL is obviously reduced with shrouded and the depressor effect is better with the higher gear speed.