水土保持学报2023，Vol.37Issue(6)：18-24,33,8.DOI:10.13870/j.cnki.stbcxb.2023.06.003
基于PIV的渐变地表粗糙度对坡面流水动力特性的影响
The Influence of Gradient Surface Roughness on the Hydrodynamic Characteristics of Overland Flow Based on PIV
摘要
Abstract
Roughness is a key factor affecting the hydrodynamic characteristics of overland flow.In order to explore the hydraulic characteristics of overland flow under the influence of gradient roughness,using particle image velocimetry(PIV)to observe and analyze the velocity profile,turbulence intensity,Reynolds stress and wall shear stress of the overland flow under the three groups of flow rates.The results showed that:(1)The flow velocity decreased with the increase of roughness;the logarithmic formula of velocity distribution was obtained by fitting the dimensionless velocity.The increase of roughness was inversely proportional to the fitting constant A and proportional to the integral coefficient B.(2)The trend of streamwise turbulence intensity of gradient surface roughness was similar to that of smooth bed slope.The streamwise turbulence intensity decreased with the increase of relative water depth.With the increase of roughness,there was a nonsignificant difference in the intensity of streamwise turbulence.The turbulence intensity under the gradient rough bed was consistent with the Nezu empirical formula,and the flow rate was proportional to the empirical coefficient.(3)Under different flow rates,the Reynolds stress distribution of the graded rough bed was similar to that of the smooth bed.Under the influence of roughness,the maximum Reynolds stress appeared at y/H = 0.2～0.4.With the increase of roughness,the wall shear stress increased gradually.The synthesis showed that the method of increasing PIV resolution could be applied to the study of hydraulic characteristics of overland flow.Exploring the influence of gradient roughness on slope flow and exploring the hydrodynamic characteristics of slope flow provide new ideas for theoretical research of soil and water conservation.关键词
水动力特性/坡面流/粒子图像测速技术(PIV)/渐变粗糙床面/粗糙度Key words
hydraulic characteristic/overland flow/particle image velocimetry(PIV)/gradient rough bed surface/roughness分类
农业科技引用本文复制引用
谷方正,张会兰,王铃涵,夏绍钦,孙虎..基于PIV的渐变地表粗糙度对坡面流水动力特性的影响[J].水土保持学报,2023,37(6):18-24,33,8.基金项目
国家自然科学基金项目(52279056) （52279056）
"十四五"重点研发计划项目(2022YFF130009505) （2022YFF130009505）
