The method, based on the theory of non-symmetric flow in Lavol nozzle, aims first at the Angle of reducing the gas dynamic misalignment, and then at the Angle of efficiency.

According to the shortcomings of traditional time domain Fourier transform, one new method of Angle domain Fourier transform is put forward at first time, and theoretical formulas are deduced.

First of all, it put forward the method by designing suitable slope angle of the pitched roof that can save the planning place.