【作者】 李明明；

【导师】 李杰；

【作者基本信息】 北京理工大学 ， 兵器工程， 2015， 硕士

【摘要】 随着微小型无人飞行器应用越来越普遍,电动力系统作为最适用的动力系统之一,其续航问题越来越受到人们的关注。在无法减小飞行器质量以及电池密度无法提高的前提下,只能通过提高系统的效率来提高续航时间。其中螺旋桨、螺旋桨与电机的匹配两方面对电动力系统效率的影响占主要因素,故本文通过提高螺旋桨效率和提高匹配效率两个方面来对电动力系统进行优化设计。首先,本文详细介绍了目前国内外螺旋桨气动分析理论,结合本课题中微小型无人飞行器所用螺旋桨的特点进行比较分析,选择片条理论作为本文螺旋桨的气动分析理论;在详细介绍片条理论的计算原理后,建立螺旋桨的气动计算模型,并对某螺旋桨进行气动仿真计算,通过与实验结果的比较,验证出该气动分析理论应用于分析本课题螺旋桨的正确性。其次,在验证片条理论合适的基础上,通过比较目前螺旋桨优化设计的方法,选择Betz法作为螺旋桨的优化设计方法;将片条理论与Betz法结合,给出详细的优化设计方法,并描述了整个优化设计流程以及建立螺旋桨的优化设计模型;通过该模型对螺旋桨进行优化设计,给出优化设计后螺旋桨详细的结构参数以及三维示意图。然后,本文进一步对优化后螺旋桨的各个工作状态进行深入分析,分别对优化的螺旋桨在动拉力与静拉力的工作状态下进行性能计算,并与实验测试结果进行比较分析,验证优化方法的有效性;同时考虑到由静拉力计算动拉力的重要性,本文通过理论分析给出螺旋桨静拉力与动拉力之间的数学关系,并给出相应参数的计算方法。最后,在已知螺旋桨的基础上,建立电机数学模型并与螺旋桨的气动模型联立,通过比较分析不同电机与螺旋桨组合的性能曲线来选择出较优的匹配结果,从而完成电机与螺旋桨的匹配优化设计。更多还原

【Abstract】 With the widespread application of MAV, the endurance of electric propulsion system that one of the most suitable power systems has received more and more attention. On the premise that the quality of aircraft could not be reduced and battery density could not be improved, improving efficiency is the only way to increasing endurance of electric propulsion. This paper will concentrate on improving efficiency of propellers and the matching between motor and propeller because the influence of the two items is far more significant.Firstly, this article introduces most of the existing the aerodynamic theories in details, combined with the characters of propellers of MAV, this paper chose strip analysis theory as the aerodynamic theory. After introducing the strip theory and establishing the propeller model, the correctness of this theory for this paper’s propellers is verified by comparing simulation results with experimental results.Secondly, on the basis of proving the strip theory appropriate and comparison of the current optimization methods, Betz theory is chosen as the optimizing theory. Combined Betz theory with the strip theory, a method of optimizing propellers is reported and the whole process of design propellers also is described. After optimizing propeller by using the method, the structural parameters and 3D schematic diagram of the optimized propeller is reported.Then, this paper analyze the performance of propellers at different operating conditions. And the performance of optimized propeller at static state and dynamic state also is calculated. Moreover because of the importance of computing dynamic tension by static tension, the relationship between static tension and dynamic tension is described, and the calculation method of the parameters also is reported.Finally, in the case of given propeller and combined the motor model with the propeller model, the better matching result could be chosen by comparing the performance of matching different motors for propeller, and the aim of optimizing design the match of motor and propeller could be accomplished.更多还原