• 论文 •

### 基于K-FWH声比拟方法的串列双圆柱气动噪声研究

1. 南京理工大学 能源与动力工程学院, 南京 210094
• 收稿日期:2020-07-28 发布日期:2021-11-08
• 通讯作者: 周毅 E-mail:yizhou@njust.edu.cn
• 基金资助:
国家重点研发计划（2019YFE0104800）

### Investigation on aeroacoustic of tandem double cylinders by K-FWH acoustic analogy method

CHEN Wu, ZHOU Yi

1. School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
• Received:2020-07-28 Published:2021-11-08

Abstract: To study the intrinsic relation between the aerodynamic noise of tandem double cylinders and the large-scale vortex shedding behavior, we carry out large eddy simulations combined with the K-FWH equation. Firstly, the high-fidelity of the numerical treatment is verified by a comparison with the corresponding experimental results, and it has been proved that the combination of Wall Adaptive Local Eddy (WALE) viscosity model and K-FWH equation can accurately predict the distribution of noise spectrum density under different frequencies. The numerical results show that the vortex shedding frequencies of the upstream and downstream cylinders are the exactly same and the large-scale vortex shedding prove to be antiphase shedding. The mean surface drag coefficient of the upstream cylinder is larger than that of the downstream cylinder, but the pressure fluctuations on the downstream cylindrical surface are much more significant. The main contribution of the aerodynamic noise generated by flow around tandem cylinders is the dipole noise term (i.e. effects of the instantaneous pressure on the cylinder surface and the time derivative of the pressure), in which the time derivative of instantaneous pressure is the dominant component of sound pressure. The physical correlation between the instantaneous sound pressure and the lift and drag forces at a selected observation point is also explored. It is shown that the instantaneous sound pressure is mainly dominated by the sound pressure generated by the downstream cylinder. Owing to the influence of the upstream vortex shedding on the downstream cylinder vortex shedding, the downstream lift coefficient spectrum and the total noise spectrum exhibit discernable secondary peaks. Furthermore, by the Hilbert transform, it is found that the acoustic pressure strength at the observation point is not affected by the phase difference of the upstream and downstream vortex shedding. This research contributes to the understanding of the reduction of the aerodynamic noise of tandem double cylinders and sheds light on the engineering noise reduction.