Sponsor
This study was supported by the “Taishan” Talents program (tsqn202312103). XZ acknowledges Portland State University Faculty Developments Grant (No.FDG-FEAXYZ) and Anvil platform through the allocation from the ACCESS program (No.MCH230024).
Published In
International Journal of Heat and Fluid Flow
Document Type
Post-Print
Publication Date
2025
Subjects
Wind power, Wind forecasting, Boundary layer (Meteorology), Atmospheric turbulence -- Mathematical models
Abstract
Wind energy has become increasingly crucial among renewable energy resources, and as the prerequisite for effective wind energy utilization, accurate wind resource assessments are hence prominent. Topography significantly affects near-surface wind fields and is thus an essential factor to be considered for wind resource assessment. However, few studies have addressed the wind resource distribution downwind of spanwise-heterogeneous terrains, which are frequently encountered in both natural and urban environments. To fill this gap, large eddy simulations were performed to investigate wind distributions over a uniform terrain downwind of terrains featuring spanwise-alternating strips of low and high surface roughness, and the high roughness surface coverage ratio λ is varied from 12.5% to 100%. The analysis focuses on the wind speed within the turbine blades region, and two dominant mechanisms are identified: the rough-to-smooth transition (RST) and spanwise heterogeneity of momentum (SHM). The dominance of the two mechanisms depends strongly on λ, with RST dominating over SHM as λ increases. Moreover, RST initially increases the wind speed due to the growth of the internal boundary layer but leads to a decrease of wind speed further downwind as the internal boundary layer rearranges. SHM results from secondary flows induced by the heterogeneous terrain upwind, which decay downwind. As λ increases, secondary flow structures transition from asymmetric to symmetric patterns, and lower λ leads to asymmetric flows, sustaining momentum heterogeneity farther downwind. Hence, upwind spanwise heterogeneous terrains can significantly impact the wind speed distribution, and suggestions are made for wind farm planning based on the results.
Rights
Copyright 2025 Licensed under CC BY-NC-ND 4.0
DOI
10.1016/j.ijheatfluidflow.2025.110182
Persistent Identifier
https://archives.pdx.edu/ds/psu/44357
Citation Details
Xu, H. H., Yu, T., Cal, R. B., & Zhu, X. (2026). Effects of the upwind spanwise heterogeneous terrain on the wind resource distribution. International Journal of Heat and Fluid Flow, 118, 110182.
Description
This is the accepted manuscript subsequently published by Elsevier.
The definitive version can be found on the publisher website. https://doi.org/10.1016/j.ijheatfluidflow.2025.110182