基于不确定性的旋翼转速优化直升机参数设计

为了提高旋翼转速优化直升机总体参数设计质量，基于不确定性多学科设计优化方法，对旋翼转速优化直升机的参数设计进行了研究。首先对最优旋翼转速的不确定性进行分析与建模，同时也考虑了直升机加工制造、材料老化引起的不确定性因素，对比发现最优旋翼转速是旋翼转速优化直升机设计中的主要不确定性因素；然后在协同优化框架下，分别建立了直升机飞行性能、直升机重量、飞行稳定性与变转速涡轴发动机性能计算模型；最后以续航性能为系统学科，悬停性能、飞行稳定性分别作为子学科，进行多学科的不确定性优化设计，得到了3种不确定性优化设计方案。通过对比分析可以发现：第2种方案为旋翼转速优化直升机的最佳参数设计方案，该方案满足悬停需用功率低于350 kW，飞行稳定性指数小于0.8等约束条件的概率不低于95.46%，并且直升机的最大航时期望值也较大。

Parameter design of helicopter with optimum speed rotor based on uncertainty optimization

In order to improve the quality of design schemes of helicopter with optimum speed rotor, this paper studies the design method of helicopter with optimum speed rotor, based on uncertainty multidisciplinary design optimization. First of all, the uncertainty factors of helicopter parameters are analyzed and modeled from optimal rotor speed, processing error and material deterioration, and it shows that the optimal rotor speed is the main uncertainty factor in the design of helicopter with optimum speed rotor. And then under the collaborative optimization framework, the models of helicopter flight performance, helicopter weight, flight stability, and the performance of turboshaft engine with variable rotor speed are established. Finally, the design of helicopter with optimum speed rotor based on uncertainty multidisciplinary optimization is investigated, which is based on two subsystem design tasks, i.e., hovering performance and flight stability, and one system level design task about helicopter endurance. Optimization results show that the second scheme for the helicopter with the optimum speed rotor is the best one; its probability of satisfying the constraints of required power being less than 350 kW in hover and index of flight stability being less than 0.8, is not less than 95.46%, and expectation of endurance is also bigger.