LES study of topographical effects of simplified 3D hills with different slopes on ABL flows considering terrain exposure conditions. Issue 210 (March 2021)

• Record Type: Journal Article
• Authors: Yang, Qingshan; Zhou, Tong; Yan, Bowen; Liu, Min; Van Phuc, Pham; Shu, Zhenru
• Is Part Of: Journal of wind engineering and industrial aerodynamics. Issue 210(2021)
• Publication Date: 2021-03
• Subjects: Large-eddy simulation -- Topographical effect -- Wind shear coefficient -- Turbulence intensity -- Non-gaussianity -- Wind farm siting; Wind-pressure -- Periodicals; Buildings -- Aerodynamics -- Periodicals; Pression du vent -- Périodiques; Constructions -- Aérodynamique -- Périodiques; Buildings -- Aerodynamics; Wind-pressure; Periodicals
• DOI: 10.1016/j.jweia.2020.104513
• Languages: English
• ISSNs: 0167-6105

Abstract

Abstract: The oncoming turbulence is of particular importance with respect to the investigation of the turbulent flow fields over hilly terrain, which plays an essential role regarding the optimization of micro-siting of the wind farm and reasonable structural design of wind turbines. In this study, large-eddy simulations (LES) are performed to elucidate the effects of wind shear coefficients (WSCs) and upstream turbulence intensities (TIs) on the complex wind flow fields over the simplified 3-D hills. Systematical analysis of the wind turbulence properties related to the micro-siting and fatigue loads of wind turbines, including fractional speed-up ratio (SUR), terrain-induced TI, velocity spectrum and wind speed probability density function, is performed in a quantitative manner. Stronger non-Gaussianity is identified in the wake of gentle-sloped and moderate-sloped hills, which is weakened by increased WSC and enhanced TI. In addition, remarkable SURs are observed mostly at the summit of a steep-sloped hill near the hill surface, and the fractional speed-up factor is found to increase significantly under higher WSC and larger TI. Furthermore, the influence of topography on the wind direction field is also examined, which shows little dependence on the WSCs and TIs. Highlights: The effects of wind shear coefficients and upstream turbulence intensities on the turbulent flow fields over complex terrain are clarified. Various wind turbulence properties related to the micro-sitting and fatigue loads of wind turbines are examined. The influence of curved topography on the vertical distribution of wind speed and wind direction are identified.