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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2017, Vol. 38 ›› Issue (10): 121000-121000.doi: 10.7527/S1000-6893.2017.121000

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Rotor noise reduction mechanism and parameter analysis of HHC method

CHEN Siyu, ZHAO Qijun, NI Tongbing, ZHU Zheng   

  1. National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
  • Received:2016-11-28 Revised:2017-06-06 Online:2017-10-15 Published:2017-06-06
  • Supported by:

    National Natural Science Foundation of China (11572156);Jiangsu Innovation Program for Graduate Education (KYLX15_0250);Priority Academic Program Development of Jiangsu Higher Education Institutions

Abstract:

Rotor blade-vortex interaction (BVI) noise is one of the main objectives of rotor aerodynamic noise reduction.The higher harmonic control (HHC) method has been demonstrated to be an effective rotor noise reduction method.To obtain noise reduction effects,noise reduction mechanism and parameter effects of the HHC method,a CFD method for simulating blade-vortex interaction is established based on moving-embedded grid method and compressible Reynolds averaged Navier-Stokes (RANS) equations.Based on the previous flowfield calculations and FW-H equations,a noise prediction method CFD/FW-H is established to predict the BVI noise.The case of BO-105 rotor with HHC is calculated using the proposed method.The calculation results obtained by simulating different CFD cases demonstrate that the sound pressure levels of the case with HHC are reduced by 4-7 dB during low speed descent.The effects of the frequency,phase and the amplitude of HHC on rotor BVI noise control have been analyzed.Some conclusions about relative parameter effect rules have been obtained and the mechanism of HHC has been further explained based on the influence of amplitude on noise reduction effects of HHC.

Key words: rotor BVI noise, RANS equations, FW-H equations, higher harmonic control (HHC), parameter analysis, noise reduction mechanism

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