干旱区地理2023，Vol.46Issue(12)：1973-1983,11.DOI:10.12118/j.issn.1000-6060.2023.197
附面层位移厚度对沙障防风效益评价的适用性研究
Applicability study of the boundary layer displacement thickness to the evaluation of sand barrier windbreak benefits:A case of polylactic acid sand barrier
摘要
Abstract
Surface roughness,a conventional index widely applied in wind erosion protection,plays a crucial role in evaluating the effectiveness of engineering measures such as forest and sand barriers.Despite its prevalent use,practical applications reveal its limited accuracy.Consequently,we introduce a novel index termed"boundary lay-er displacement thickness".Through wind tunnel simulations,we assessed the wind speed frequency distribution of various sandbag barriers.We computed the mean wind speed,wind prevention efficiency,and also scrutinized the wind speed flow field to validate the precision of both roughness and boundary layer displacement thickness measurements.The findings indicate that an increase in the length of the polylactic acid sandbag barrier corre-sponds to an upward trend in average wind speed.Specifically,the average wind speed within the 1.5-m and 2.0-m barriers is 1.13 and 1.24 times that of the 1.0-m barrier,respectively.Concurrently,wind prevention efficiency ex-periences a decline,with values exceeding 0.6 for the 1.0-m barrier,0.5 for the 1.5-m barrier,and 0.4 for the 2.0-m barrier.Analysis of the wind velocity field data reveal that the high-speed zone expands as the barrier grid size in-creases,signifying a weakened protective effect with large sand barriers.Notably,the boundary layer displace-ment thickness demonstrates a consistent decreasing trend with increasing barrier size,aligning with the afore-mentioned pattern.However,surface roughness exhibits an anomalous pattern,initially decreasing and then in-creasing.In summary,the boundary layer displacement thickness proved to be more accurate and emerged as a promising supplementary reference indicator for evaluating the efficacy of wind erosion protection measures.关键词
附面层位移厚度/风蚀评价/风洞模拟/聚乳酸沙障Key words
boundary layer displacement thickness/wind erosion evaluation/wind tunnel simulation/polylac-tic acid sand barrier引用本文复制引用
张帅,原伟杰,刘卉,王海霞,官昊慧,王鹿振..附面层位移厚度对沙障防风效益评价的适用性研究[J].干旱区地理,2023,46(12):1973-1983,11.基金项目
国家自然科学基金青年基金项目(32001375) （32001375）
国家林业和草原局科技创新青年拔尖人才项目(2019132604) （2019132604）
林业科学技术推广项目([2019]34)资助 （[2019]34）
