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为研究不同形式的新型桨尖在抑制旋翼跨声速噪声特性方面的作用机理,以UH-1H模型旋翼为基准,开展了多种后掠和前掠桨尖对旋翼高速脉冲噪声特性的数值分析研究。采用积分形式的可压缩雷诺平均NavierStokes(RANS)方程作为旋翼流场求解控制方程,时间推进方法采用高效的隐式LU-SGS格式,空间方向采用高精度的Roe-MUSCL格式,湍流模型选用Baldwin-Lomax模型。在CFD方法验证基础上,采用基于可穿透旋转积分面的鲁棒性较好的FW-H_pds方程来求解旋翼高速脉冲(high-speed impulsive,HSI)噪声,并通过对UH-1H模型旋翼的跨声速噪声的计算,验证了噪声预测方法的有效性。在此基础上,研究了在不同桨尖马赫数下的旋翼桨尖附近的离域化(delocalization)现象以及高速脉冲噪声特性,通过四极子噪声和单极子噪声的对比分析,揭示了旋翼跨声速噪声产生机理。然后,着重研究了不同外形参数的后掠和前掠桨尖旋翼在抑制旋翼跨声速特性方面的影响规律。计算结果表明:随着桨尖马赫数的增加,旋翼高速脉冲噪声辐射愈加强烈,离域化现象愈加明显;后掠和前掠桨尖旋翼均可以不同程度地减弱激波强度,能有效抑制离域化现象的产生,从而降低旋翼跨声速噪声水平;前掠桨尖旋翼还可以驱使激波位置向桨叶内侧移动,减弱其对桨叶外部空间区域的影响,能更有效地抑制离域化现象的产生。
In order to study the action mechanism of different types of new tip in the suppression of rotor transonic noise, a numerical study on the characteristics of high speed impulse noise of a rotary blade with a variety of sweep and forward swept tip is carried out based on UH-1H model rotor . Integral compressible Reynolds-average NavierStokes (RANS) equations are used to solve the control equations of the rotor flow field. The time advance method adopts the highly efficient implicit LU-SGS format, the spatial orientation adopts the high accuracy Roe-MUSCL format, and the turbulence model uses the Baldwin- Lomax model. Based on the CFD method validation, a robust FW-H_pds equation based on penetrating the rotating integral surface is used to solve the HSI noise. The HSI noise of the UH-1H model rotor The calculation of transonic noise verifies the effectiveness of the noise prediction method. Based on this, delocalization and high-speed impulsive noise near the tips of rotor blades under different blade Mach numbers are studied. By comparing and analyzing the quadrupole and unipolar noise, it is revealed that the rotor Transonic noise generation mechanism. Then, the influence laws of swept-back rotor and front-swept-tip rotor with different shape parameters in suppressing the transonic speed characteristics of the rotor are emphatically studied. The results show that with the increase of Mach number, the high-speed impulsive noise radiation of rotor is more intense and the de-localization phenomenon becomes more obvious. Both swept back sweep and forward swept tip rotor can reduce the shock intensity to some extent, Domain formation phenomenon, thereby reducing the rotor transonic noise level; forward swept tip rotor can also drive the shock wave position to the inside of the blade to move, weakened its impact on the outer space of the blade area, can more effectively inhibit the delocalization Phenomenon generation.