Inlet shunt stability extension design method suitable for contra-rotating lift fan

Abstract

The invention discloses an inlet shunt stability extension design method suitable for a contra-rotating lift fan, which is characterized in that a spline interpolation method is utilized to reconstruct a molded line of an end wall of a casing at an inlet section of the fan, the reconstructed casing end is in a curved cone shape, and a cone angle is in smooth transition from an inlet of a lift device to the inside of an inlet guide vane; a circumferential diversion through groove is communicated and designed between the front edge of the inlet guide vane and the position close to the front edge of the first-stage rotor, and the area of the through groove is gradually reduced from an inlet to an outlet. According to the invention, the layout mode that air is entrained from the rear stage to the front stage in the traditional self-circulation stability expansion is changed, so that the performance loss of the rear stage is fundamentally reduced; by means of the curved surface conical design of the inlet, flow deterioration of the blade tip of the inlet guide blade caused by flow division of an inlet pipeline is restrained; the advantage that the magnitude of the pressure difference between the front end of an inlet guide vane and the front edge of a rotor is low is utilized, so that the inlet flow consumed by a flow dividing pipeline is very limited, and the harmful offset effect of a whole machine performance curve is weak. And the method is effective for horizontal lift fans with various rotating speed conditions and various stages of loads.

Description

technical field [0001] The invention relates to the technical field of counter-rotating lift fans for aviation, in particular to a design method for inlet diversion and stability expansion of counter-rotating lift fans, and is especially suitable for weakening the separation of first-stage rotor blade tips of counter-rotating lift fans and expanding counter-rotating lift devices The case of stability margins. Background technique [0002] The counter-rotating lift propulsion fan plays an important role as a power source during the take-off and landing of short vertical take-off and landing aircraft, and its stability determines the safety of its landing process. Due to the harsh operating environment of short vertical take-off and landing aircraft, and the limited flow stabilization section at the entrance of the lift propulsion system, the instability problem faced by the first-stage rotor blade tip is more prominent when it is distorted or even flows smoothly. Therefore, ...

AI Technical Summary

Problems solved by technology

Essentially, the driving force of the fluid in the self-circulation communication tank still comes from the work of the impeller, which will inevitably lead to a decrease in the theoretical work downstream of the impeller.

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