Analysis of POD and EPOD for Unsteady Flow Field of Wind Turbine Airfoil

doi:10.16183/j.cnki.jsjtu.2020.204

Abstract

Abstract:

The profile flow around the wind turbine airfoil has a significant impact on the overall performance and the noise of a wind turbine. In this paper, a combination method of large eddy simulation (LES) and the solution of Ffowcs Williams and Hawkings (FW-H) equation is used to obtain the unsteady flow field and the far-field aeroacoustic noise of a wind turbine airfoil. The dominant modes of the unsteady vorticity at the angle of attack of 8° are extracted by the proper orthogonal decomposition (POD). The modal structure of the dominant modes indicates that the trailing edge vortices and the laminar separation bubble are the main unsteady feature of the airfoil flow. The modal structures most related to the far-field aeracoustics noise are obtained by the extend proper orthogonal decomposition (EPOD). The modal results show that the vortices in the boundary layer and the large-scale vortices in the wake are most relevant to the generation and propagation of the aeracoustics noise.

Key words: profile flow, large eddy simulation (LES), aeroacoustic noise, proper orthogonal decomposition (POD)

CLC Number:

TK83

SUN Chong, TIAN Tian, ZHU Xiaocheng, DU Zhaohui. Analysis of POD and EPOD for Unsteady Flow Field of Wind Turbine Airfoil[J]. Journal of Shanghai Jiao Tong University, 2022, 56(1): 45-52.

Figures/Tables 9

Fig.1

Fig.2

Fig.3

Fig.4

Fig.5

Fig.6

Fig.7

Fig.8

Fig.9

References 15

[1]	MCKENNA R, OSTMAN V D, LEYE P, FICHTNER W. Key challenges and prospects for large wind turbines[J]. Renewable and Sustainable Energy Reviews, 2016, 53:1212-1221. doi: 10.1016/j.rser.2015.09.080 URL
[2]	王国章, 李小龙, 张俊霞, 等. 大型风力机的噪声源产生机制实验研究[J]. 压电与声光, 2016, 38(5):829-832.
	WANG Guozhang, LI Xiaolong, ZHANG Junxia, et al. Experimental study on the noise sources generation mechanism of large wind turbine[J]. Piezoelectrics & Acoustooptics, 2016, 38(5):829-832.
[3]	张兆德, 徐超. 基于CFD的二维风力机翼型噪声分析[J]. 太阳能学报, 2016, 37(9):2180-2186.
	ZHANG Zhaode, XU Chao. Noise analysis of two-dimensional wind turbine airfoil based on cfd[J]. Acta Energiae Solaris Sinica, 2016, 37(9):2180-2186.
[4]	LIU W Y. A review on wind turbine noise mechanism and de-noising techniques[J]. Renewable Energy, 2017, 108:311-320. doi: 10.1016/j.renene.2017.02.034 URL
[5]	RAMAN G, RAMACHANDRAN R C, ALDEMAN M R. A review of wind turbine noise measurements and regulations[J]. Wind Engineering, 2016, 40(4):319-342. doi: 10.1177/0309524X16649080 URL
[6]	刘鹏寅. 水平轴风力机翼型非定常气动特性研究[D]. 上海: 上海交通大学, 2016.
	LIU Pengyin. A study on unsteady aerodynamic characteristics of airfoil for horizontal axis wind turbine[D]. Shanghai: Shanghai Jiao Tong University, 2016.
[7]	董圣华, 史爱明, 叶正寅, 等. 超临界翼型跨声速抖振CFD计算和POD分析[J]. 空气动力学学报, 2015, 33(4):481-487.
	DONG Shenghua, SHI Aiming, YE Zhengyin, et al. CFD computation and POD analysis for transonic buffet on a supercritical airfoil[J]. Acta Aerodynamica Sinica, 2015, 33(4):481-487.
[8]	ZHAO M, ZHAO Y J, LIU Z X, et al. Proper orthogonal decomposition analysis of flow characteristics of an airfoil with leading edge protuberances[J]. AIAA Journal, 2019, 57(7):2710-2721.
[9]	BORÉE J. Extended proper orthogonal decomposition: A tool to analyse correlated events in turbulent flows[J]. Experiments in Fluids, 2003, 35(2):188-192. doi: 10.1007/s00348-003-0656-3 URL
[10]	SCHLEGEL M, NOACK B R, JORDAN P, et al. On least-order flow representations for aerodynamics and aeroacoustics[J]. Journal of Fluid Mechanics, 2012, 697:367-398. doi: 10.1017/jfm.2012.70 URL
[11]	YU G H, ZHU X C, DU Z H. Numerical simulation of a wind turbine airfoil: Dynamic stall and comparison with experiments[J]. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 2010, 224(5):657-677. doi: 10.1243/09576509JPE942 URL
[12]	刘鹏寅, 陈进格, 沈昕, 等. 风力机翼型在大攻角流场下的动力模态分解分析[J]. 上海交通大学学报, 2017, 51(7):805-811.
	LIU Pengyin, CHEN Jinge, SHEN Xin, et al. Analysis of dynamic mode decomposition for wind turbine airfoil flow field at high angle of attack[J]. Journal of Shanghai Jiao Tong University, 2017, 51(7):805-811.
[13]	TAIRA K, BRUNTON S L, DAWSON S T M, et al. Modal analysis of fluid flows: An overview[J]. AIAA Journal, 2017, 55(12):4013-4041. doi: 10.2514/1.J056060 URL
[14]	RAMSAY R F, HOFFMAN M J, GREGOREK G M. Effects of grit roughness and pitch oscillations on the S809 airfoil [EB/OL]. (1995-12-01) [2020-06-17]. https://www.osti.gov/biblio/205563-GvbHua/webviewable/.
[15]	杨海华. 亚声速射流噪声的数值模拟与机理研究[D]. 合肥: 中国科学技术大学, 2016.
	YANG Haihua. Numerical investigations of sound generation in subsonic jets[D]. Hefei: University of Science and Technology of China, 2016.