Cruise propeller matching optimization method suitable for piston power unmanned aerial vehicle

Abstract

The invention discloses a cruise propeller matching optimization method suitable for a piston power unmanned aerial vehicle. The method comprises the following steps of: introducing a required thrust matching coefficient CR by taking thrust required for aircraft cruise as an entry point and utilizing a thrust coefficient and a forward ratio so as to eliminate coupling characteristics of a propeller speed and an engine speed, and establishing a corresponding relation between the engine speed and propeller efficiency; the minimum unit thrust fuel consumption (SFC) serves as a design target, matching working points of an engine and a propeller are selected, the optimal engine rotating speeds corresponding to different air doors of the engine are set, the minimum cruising fuel consumption is achieved on the premise that the cruising thrust requirement is met, and an aircraft can obtain the optimal endurance performance. The selection process of the matching working points of the engine and the propeller is greatly simplified, and the matching working efficiency of the propeller engine of the piston propeller power unmanned aerial vehicle is remarkably improved; and a design basis can be provided for a wind tunnel test of a complete machine with a propeller, engine control logic rotating speed setting and the like, and finally, the flight endurance performance of the aircraft is optimized and improved.

Description

technical field [0001] The invention belongs to the technical field of aircraft performance design, and in particular relates to a cruise propeller-engine matching optimization method suitable for a piston-powered unmanned aerial vehicle. Background technique [0002] The piston propeller power system has the characteristics of small size, light weight, low fuel consumption, and low price. It is widely used in various small, low-speed manned and unmanned aircraft, such as patrol inspection, survey and mapping, manual distribution, branch freight, etc. . The typical use of this type of aircraft is generally based on cruising flight along a fixed route, with a designed cruising altitude and speed. Therefore, choosing a suitable engine and propeller to match the operating point is important for reducing flight fuel consumption, improving aircraft endurance, and increasing flight time. Economics is important. In the early days of the birth of the propeller aircraft, the charac...

AI Technical Summary

Problems solved by technology

[0005] Among the published UAV propeller-engine matching technologies, patent CN110937130A discloses a propeller-engine matching optimization method suitable for long-endurance turboprop-powered UAVs. This method is only applicable to turboprop-powered UAVs with free turbines. , for a piston engine with a fixed gearbox reduction ratio, the propeller speed is fixedly connected to the engine speed. When the propeller speed is optimized, it will cause a linkage change in the engine speed, resulting in a change in the engine output power. Therefore, the aforementioned patented technology The method of optimizing the propeller speed under the premise of determining the engine speed is not suitable for piston engines with a fixed gearbox reduction ratio

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