Axial ultrasonic through-flow fan serial configuration and serial configuration optimization method

Abstract

The invention discloses an axial supersound through-flow fan serial configuration and a configuration optimization method, and belongs to the technical field of aerodynamic layout of aerospace turbomachinery. The axial bending moment of a single blade under the axial ultrasonic incoming flow condition is reduced by adopting a serial blade structure, the stability of the blade grid structure is enhanced, and the flutter instability of the blades is avoided. The rear-row blades are located on the suction sides of the front-row blades in the circumferential direction, a shock wave structure near gaps formed by the front-row blades and the rear-row blades is improved by adjusting the circumferential pitch ratio, the wakes of the front-row blades are attached to the pressure faces of the rear-row blades, the mixing degree of the wakes of the front-row blades and the boundary layers of the surfaces of the rear-row blades is restrained, and the noise is reduced. And the pneumatic total pressure loss is reduced. The pneumatic total pressure loss is further reduced by adjusting the circumferential pitch ratio and the axial overlapping degree. By adjusting the axial overlapping degree, it is avoided that due to the fact that the axial overlapping degree is too small, fluid on the pressure face of the front-row blade flows to the suction side of the rear-row blade, and the wake thickness of the front-row blade is increased.

Description

technical field [0001] The invention relates to a configuration of aeroengine fan blades, in particular to a tandem configuration of axial supersonic through-flow fans, and belongs to the technical field of aerodynamic layout of aerospace impeller machinery. Background technique [0002] In order to explore a new aerodynamic layout method suitable for the compression system of a supersonic engine, in order to greatly reduce the weight of the compression system and increase the thrust-to-weight ratio, NASA proposed the concept of an axial supersonic ventilation fan, that is, the axial speed of the inlet and outlet of the fan stage is uniform. for supersonic speed. Compared with the conventional turbofan engine, the axial supersonic ventilation fan no longer needs a lengthy air inlet to decelerate and diffuse the supersonic incoming flow into a subsonic incoming flow on the windward side of the fan, thus greatly shortening the length of the air inlet , under typical aerodynam...

AI Technical Summary

Problems solved by technology

Although the axial supersonic through-flow fan has many advantages above, the blades of the axial supersonic through-flow fan will bear excessive torsional bending moment when operating at a high angle of attack due to the high Mach number of the incoming flow, which is likely to cause flutter Instability, leading to blade fatigue fracture failure in a short time

In order to weaken the strong torsional vibration mode flutter and enhance the stability of the cascade structure, the traditional method is to use the adjustable blade technology, but the typical design characteristics of the axial supersonic through-flow fan blades are high in consistency and long in chord. Structurally difficult to achieve

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