平流层飞艇三叶螺旋桨结构优化方法

In order to achieve propeller's trade⁃off design between light mass and high natu⁃ ral frequency，a partition optimization method of symmetrical cutting layer structure for its blade was developed. For broadening its speed and height range of high efficiency，variable pitch tech⁃ nology should be adopted，and cylindrical blade root should be designed. The blades were assem⁃ bled with the hub of different pitch angles，which can realize manual variable pitch and reach the high altitude rotate speed in ground test. A combined split hub layout，foam⁃filled form inside the blades， and carbon fiber hybrid structure in the propeller were adopted， the laying parameters optimization of fixed⁃supported propeller blades was finished based on the NSGA⁃Ⅱ（non⁃domi⁃ nated sorting algorithm），and Pareto solution set of blade mass and frequency was obtained. The optimal laying scheme was selected outside the ±10% of frequency safety margin， and com⁃ pared with test values of the actual prototype. The results showed that the relative error of blade mass was 2. 09%，the relative error of single blade frequency on fixed support was 9. 30%，and the relative error of the combined frequency of three blades and the hub on fixed support was 2. 76%. This avoided resonance region of the working rotate speed，proving that the structure op⁃ timization method is reasonable and effective.