基于时域气声伴随算法的直升机转子叶片形状优化分析

Optimal Analysis of Helicopter Rotor Blade Shape Based on Air Acoustic Adjoint Algorithm in Time Domain

针对直升机噪声问题,基于空气动力学原理和全耦合气动声学分析公式,构建直升机转子叶片灵敏度分析模型,采用ANSYS CFX数值模拟方法与FW-H声学模块耦合的混合气动声学方法,将直升机转子噪声信号传播给远场观测者。利用时域气声伴随算法实现模型求解,选取四叶NACA0012型直升机旋翼在前飞工况的噪声进行实证研究,结果表明模型能有效地预测四叶NACA0012旋翼在前飞时的噪声。在验证成功的基础上,采用伴随公式对旋翼噪声信号进行优化,最后得到时域气声伴随算法的直升机转子叶片形状优化分析的结果。

This paper presents a sensitivity analysis formula for helicopter aeroacoustics time-varying problems.In this paper,an ANSYS CFX numerical simulation method and a hybrid aeroacoustic method coupled with the FW-H acoustic module are used to propagate the helicopter rotor noise signal to the far-field observer.The tangential sensitivity formula and the concomitant sensitivity formula similar to the aeroacoustic analysis problem are derived.It is the first time that the fully coupled aeroacoustic analysis formula can effectively predict the noise of the four-blade NACA0012 rotor during forward flight.On the basis of successful verification,the adjoint formula is used to optimize the rotor noise signal.Finally,the results of helicopter rotor blade shape optimization analysis based on time-domain aeroacoustic adjoint algorithm are obtained.