转速优化旋翼的桨叶气动外形参数优化设计

Optimal design for aerodynamic shape parameters of optimum speed rotor

为了获得转速优化旋翼桨叶的最优气动外形,采用自由尾迹方法计算旋翼入流,以叶素积分法计算桨叶气动力,建立了旋翼气动分析模型,为了保证计算精度及效率,旋翼配平计算采用了二次配平方法。首先分析了不同桨叶气动外形参数对旋翼性能的影响,再利用遗传算法,以悬停效率和前飞需用功率为目标,对转速优化旋翼桨叶的气动外形进行优化设计,得出了转速优化旋翼桨叶的最优气动外形方案。在最优方案的基础上,采用区间因子法分析桨叶外形参数变化对旋翼效率影响的敏感度,根据敏感度值验证了方案的最优性。最后根据设计的最优桨叶气动外形方案,研制了桨叶试验模型,进行了风洞吹风试验,试验结果表明最优桨叶气动外形能使转速优化旋翼的悬停与前飞性能指标达到理论预期值,从而验证了转速优化旋翼桨叶最优气动外形设计的有效性。

An analytical model of rotor aerodynamics has been established in order to achieve the optimal aerodynamic shape parameters of optimum speed rotor ; with the model, we computed induced velocity by free-wake theory and calculated rotor aerodynamics by blade element theory. Meanwhile, accuracy and efficiency of this model were guaranteed by using secondary trim method. With the above-mentioned model, we further analyzed the influence of different blade aerodynamic shape parameters on the rotor performance. Using genetic algorithm, aimed at hover efficiency and forward flight required power, we carried out the optimal design for aerodynamic shape parameters of optimum speed rotor and obtained the optimal solution. Then based on the optimal solution, we analyzed the influence of blade shape parameters on the rotor performance sensitivity by interval factor method. The sensitivity value demonstrated the optimality of the solution. Finally, having built the blade model and carried out the wind tunnel test, the results of the test show that optimal design for aerodynamic shape parameters can make hover and forward flight performance of rotor reach the theoretical calculation values, which verify the effectiveness of the optimal design for aerodynamic shape parameters of optimum speed rotor.