基于IBC方法的旋翼BVI噪声主动控制机理  

Active control mechanism of rotor BVI noise based on IBC method

作　　者：倪同兵[1] 招启军[1] 马砾[1] 

机构地区：[1]南京航空航天大学直升机旋翼动力学国家级重点实验室,南京210016

出　　处：《航空学报》2017年第7期120-132,共13页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(11572156);江苏高校优势学科建设工程资助项目~~

摘　　要：为揭示单片桨叶控制(IBC)主动控制技术抑制旋翼桨-涡干扰(BVI)噪声的降噪机理,建立了一套基于CFD/CSD/FW-H_pds方程的综合噪声分析方法。旋翼桨-涡干扰噪声与旋翼桨叶载荷特性、气动变形以及旋翼桨尖涡结构等密切相关,为有效模拟旋翼桨叶的载荷特性及桨尖涡结构,将Navier-Stokes方程作为前飞流场的主控方程,空间离散上采用三阶MUSCL插值格式与通量差分裂Roe格式相结合;时间方向上采用双时间法,使用隐式LU-SGS格式在伪时间方向上进行推进;湍流模型采用对分离流动具有较好捕捉能力的Spalart-Allmaras模型。为提高旋翼桨叶弹性变形运动的模拟精度,建立了基于Hamilton变分原理的CSD模型,并与高精度的CFD求解器结合,发展了适合旋翼桨叶变形及载荷特性模拟的流固耦合分析方法。在CFD/CSD耦合方法分析流场基础上,使用可穿透空间积分面的FW-H_pds方法对旋翼气动噪声特性进行计算。首先,对流场及噪声数值方法进行验证;然后,着重针对UH-60A旋翼的斜下降飞行状态,分别对有/无IBC噪声主动控制条件下的旋翼BVI气动噪声特性进行了模拟,相位角、幅值和频率等不同控制参数的影响对比分析结果表明:IBC主动控制减小了前行侧桨叶表面尤其是桨叶尖部的负压峰值,降低了桨-涡干扰发生位置附近的桨叶气动载荷;同时主动控制后的桨尖涡集中程度变弱,并且增加了桨叶与桨尖涡之间的相遇距离,从而显著降低了桨-涡干扰噪声;选取合理的相位角、幅值和频率等主动控制参数组合,BVI噪声降低可达5~7dB。A CFD/CSD/FW-H_pds coupling method is established to investigate the mechanism for rotor blade-vortex interaction（BVI）noise reduction based upon individual blade control（IBC）technique.The rotor aeroacoustics is closely related to the blade deformation,the airload characteristic and the blade-tip vortex structure.In order to simulate the blade airload characteristic and blade-tip vortex structure effectively and have better capture ability for separated flows,the Navier-Stokes equations with Spalart-Allmaras turbulence model are adopted as the governing equations for the forward flight flowfield.The third-order MUSCL interpolation scheme and flux-difference splitting Roe scheme are used in spatial discretization,and the dual-time stepping method is employed in temporal discretization while the implicit LU-SGS scheme is used to march in the pseudo time step.In order to improve the calculation accuracy of elastic deformation of blade,a CSD module is developed based on Hamilton＇s variational principles.Combined with high-accuracy CFD solver,a CFD/CSD coupling strategy is developed to adapt for elastic deformation and load characteristics simulation of blades.Based upon the simulated flowfield by CFD/CSD coupling method,calculations on aeroacoustic characteristics of the rotor are conducted based on the FW-H_pds equations with the penetrable integral surface.The numerical verifications of flowfield and noise analysis methods are first completed.The aeroacoustic characteristics of the UH-60 Arotor in oblique descending flight are then calculated with and without IBC.Comparisons of the effects of different control parameters such as phase angle,amplitude and frequency on rotor aeroacoustic characteristics show that with IBC active control,the negative pressure peak of the blade surface（especially the blade-tip surface）in the advancing side decreases,resulting in decrease of the blade airloads where the BVI phenomenon occurs.In addition,with IBC,the blade-tip vortex concentration decreases,and the distance

关 键 词：旋翼 桨-涡干扰(BVI)噪声 噪声主动控制 NAVIER-STOKES方程 FW-H_pds方法 CFD/CSD耦合方法 单片桨叶控制(IBC) 

分 类 号：V211.52[航空宇航科学与技术—航空宇航推进理论与工程]