A self-adaptive pneumatic variable-pitch propeller design method

Abstract

The invention provides a self-adaptive pneumatic variable-pitch propeller design method. The concept and the method of aircraft longitudinal trimming are utilized. Under the condition that no redundant additional mechanism exists, the aerodynamic characteristics of propeller blades are designed; the method comprises the steps that a balancing principle of double-wing or duck-type layout of an analogy aircraft is adopted; the blades are designed into a double-blade layout with aerodynamic and static stability, so that the propeller has the capacity of providing a high propeller disc load, and meanwhile, the propeller can automatically change the pitch regardless of the forward ratio change caused by the change of the flight speed or the change of the rotation speed, so that the propeller has a relatively good automatic pitch change characteristic in a relatively wide flight envelope.

Description

technical field [0001] The invention relates to the technical field of aviation aircraft, in particular to an adaptive aerodynamic variable-pitch propeller design method for a small aircraft power system. Background technique [0002] Aiming at the design contradiction of the propeller in different flight states of the aircraft, a controllable pitch variable device can usually be used for large aircraft. However, for small aircraft or UAVs, the mechanism of the controllable propeller pitch variable system is too complicated, and the weight cost is relatively high. In order to find a cheaper design scheme for propeller wide envelope, some related researches have proposed some solutions. For example, Liu Chengye, Song Bifeng and others have studied a variable diameter propeller (Liu C, Song B, Wang H. Design and optimization of a variable diameter propeller[C] / / International Conference on Information Science, Electronics and Electrical Engineering. IEEE, 2014:291-295.), to e...

AI Technical Summary

Problems solved by technology

However, the inherent defects of the reverse-curved airfoil are that its trim lift coefficient is too low, and the stall characteristics at high angles of attack are poor. The designed propeller absorbs low power, which makes it unable to be used in the state of high propeller disk load, so it is not suitable for vertical airfoils. Scenarios that require high paddle loads such as taking off and landing aircraft

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