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将旋翼涡系理论与旋翼噪声计算方法相结合,建立了一个新的适用于桨-涡干扰(Blade-vortex interaction,BVI)噪声简化计算的方法。一方面,为推导桨-涡干扰噪声的解析表达式并简化运算过程,气动计算采用了基于实验的Beddoes修正涡系模型,噪声计算则使用Farassat 1A声学公式的载荷噪声项,并通过紧致源假设,实现了旋翼BVI噪声的解析推导;另一方面,为了分析直升机飞行参数对旋翼桨-涡干扰噪声的影响,将旋翼的飞行姿态与直升机旋翼气动计算模型相结合,建立了受飞行参数影响的BVI噪声声压计算模型。然后,进行了相关的算例计算,并与可得到的实验数据进行了对比,验证了所建立方法的有效性。在此基础上,应用该方法研究了桨-涡干扰状态下飞行参数对桨盘入流、桨-涡垂直间距这两个重要参数的影响,着重计算分析了斜下降飞行时出现强BVI噪声辐射的飞行航迹角和前进比范围,得出了有意义的结论。
Combining rotor vortex theory with rotor noise calculation, a new simplified method of noise reduction for Blade-vortex interaction (BVI) is established. On the one hand, in order to derive the analytic expression of propeller-vortex interference noise and simplify the calculation process, an experimental Beddoes modified vortex model is used in the aerodynamic calculation. The noise calculation uses the Farassat 1A acoustic load noise term and the compact source On the other hand, in order to analyze the influence of helicopter flight parameters on the rotor-vortex interference noise, the flight attitude of the rotor is combined with the aerodynamic calculation model of the helicopter rotor to establish the influence of the flight parameters BVI noise pressure calculation model. Then, the related calculation is made and compared with the available experimental data to verify the effectiveness of the proposed method. Based on this, the influence of the flight parameters on the two important parameters of propeller - vortex vertical distance between the propeller - vortex and the propeller - vortex under the condition of propeller - vortex interference is studied. The strong BVI noise radiation Flight path angle and forward ratio range, reached a meaningful conclusion.