Hybrid computational aeroacoustics approach based on the synthetic turbulence model in Eulerian description

Han, Xiao; Yu, Peixun; Bai, Junqiang; Zhou, Jie; Song, Xiang

doi:10.1016/j.ast.2020.106077

Cited by 7 publications

(1 citation statement)

References 30 publications

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“…10,21 However, only few literature about the use of computational aeroacoustics for helicopter rotors has been found in the public domain. 22 Acoustic propagation equation is very important for time-domain hybrid computational aeroacoustics method, 23 and many feasible and practical acoustic propagation equations are developed, such as linearized Euler equations, [24][25][26] acoustic perturbation equations, 27,28 linearized Navier-Stokes equations, 20 and nonlinear disturbance equations. 29 In this paper, the linearized Euler equations are used as the acoustic propagation equations.…”

Section: Introductionmentioning

confidence: 99%

Numerical study on the noise propagation characteristics of rotor in non-uniform downwash flowfield Based on Linearized Euler Equations

Yang

Chen

Zhao

et al. 2022

International Journal of Aeroacoustics

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To study the influence of non-uniform flowfield on the propagation characteristics of helicopter rotor noise, a Hybrid Computational Aeroacoustics (HCAA) method is developed. The acoustic source region is simulated by Computational Fluid Dynamics (CFD) technique with the Unsteady Reynolds Averaged Navier-Stokes equations (URANS) as the governing equations. Acoustic near-field is simulated by Computational Aeroacoustics (CAA) technique with the Linearized Euler Equations (LEE) as the governing equations, and the numerical discretization of the LEE is accomplished by Runge-Kutta Discontinuous Galerkin (RKDG) method. A novel acoustic source extraction method based on pressure and pressure gradient is proposed to accomplish the one-way CFD-CAA weak coupling. The HCAA method is validated through comparisons with noise experimental data of the UH-1H model rotor and the BO-105 model rotor. Based on the proposed HCAA method, the convection and refraction effects of rotor noise under different collective pitch angles are analyzed. The results show that the distortion effect of the rotor noise is most affected by the non-uniformly distributed downwash velocity field, resulting in an increment of acoustic energy below the rotor plane. The effect of non-uniformly distributed downwash velocity on noise propagation increases with the increase of the collective pitch angle. For the UH-1H model rotor, the maximum change of the sound pressure level is 0.8 dB (about 10% change of the effective sound pressure).

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Section: Introductionmentioning

confidence: 99%

Numerical study on the noise propagation characteristics of rotor in non-uniform downwash flowfield Based on Linearized Euler Equations

Yang

Chen

Zhao

et al. 2022

International Journal of Aeroacoustics

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Effects of slat track on the flow and acoustic field of high-lift devices

Chen

Yang

Tang

et al. 2022

Aerospace Science and Technology

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Analysis of aerodynamic and aeroacoustics of full scale landing gear

TIAN

Bai

et al. 2022

西北工业大学学报

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The aerodynamic noise of a landing gear is an important source of airframe noise. The analysis of its noise characteristics plays an important role in the design of a low-noise landing gear. Based on the FL-52 acoustic wind tunnel test technology, the coupled scale adaptive model and the acoustic disturbance equation, the results on aerodynamic noise of a full-scale landing gear model are analyzed. The high-fidelity model includes transverse strut, torsion arm, piston rod, wheel and other parts. The characteristics of static pressure distribution, power spectrum density of pulsating pressure, aerodynamic noise source distribution and directivity of overall sound pressure level are analyzed. The noise characteristics of the far-field microphone are compared with the local microphone installed in the wheel cavity. In this way, we characterize the directivity of pure tone in the wheel cavity and understand its contribution to the far-field noise. The results show that the aerodynamic noise of the landing gear can be quantified accurately by the hybrid numerical method. The pure tone has two frequencies inside and outside the wheel of the landing gear: 560 Hz and 960 Hz. The peak of the loudest sound pressure level reaches 136 dB, and the pure tone radiates to the surface of the non-separation area of the wheel of the landing gear. However, the wall pressure spectrum of the points located in the turbulence region shows a wide-frequency characteristic, and there is no obvious pure tone. From the point of view of the far-field noise directivity, the forward noise of the landing gear is larger than the rear noise, and there is a small overall sound pressure level area at the points of 65 and 110 degrees respectively. When the monitoring points are far away, the far-field noise of the landing gear shows the characteristics of wide frequency, and no obvious pure tone appears. The method can provide the technical support for predicting the aeroacoustics of a landing gear and designing a low-noise land gear.

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Hybrid computational aeroacoustics approach based on the synthetic turbulence model in Eulerian description

Cited by 7 publications

References 30 publications

Numerical study on the noise propagation characteristics of rotor in non-uniform downwash flowfield Based on Linearized Euler Equations

Numerical study on the noise propagation characteristics of rotor in non-uniform downwash flowfield Based on Linearized Euler Equations

Effects of slat track on the flow and acoustic field of high-lift devices

Analysis of aerodynamic and aeroacoustics of full scale landing gear

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