水土保持学报2025，Vol.39Issue(3)：335-344,351,11.DOI:10.13870/j.cnki.stbcxb.2025.03.004
基于PIV的茎秆倒伏角度对坡面薄层流水动力学特性的影响
Effect of Stem Lodging Angle on the Hydrodynamics of Thin Overland Flow on a Slope Based on PIV
摘要
Abstract
[Objective]Slope vegetation is susceptible to different degrees of collapse under the action of external forces such as water flushing and wind.The aim of the study was to investigate the influence of vegetation collapse angle on the dynamic characteristics of thin-layer flow and erosion and scouring process on slopes.[Methods]Acrylic cylinders were used to simulate the stems of the plants,and an indoor flume scouring test was carried out to set up six groups of collapse angles(45°,75°,90°,105°,135°,150°)and three sets of flow conditions(0.23,0.52,0.76 L/s),and a high-frequency Particle Image Velocimetry(PIV)system was used to capture and map the flow field,so as to analyze the effects of different stem lodging angles on the characteristics of the flow field,turbulence characteristics and vortex structural features.[Results]1)The presence of stalks caused the flow velocity at the symmetry plane of the upstream of the stems to change,forming negative flow zones along the upstream of the bed and downstream of the stalks in the near-bed region(x/D=-0.1 to x/D=-0.4,y/D=0 to y/D=0.4),and both forward and backward tilting of the stems weakened the negative flow of the water.2)The turbulence intensity of the vertical flow increased and then decreased with increasing water depth,and the locations where the maximum turbulence intensity occurred were all located near y/D=0.2,indicating that the vortex microstructure played a strong role in this region.3)The presence of stems led to the generation of Horseshoe Vortex(HV)structures at the upstream symmetry plane.Due to the weakening effect of the forward and backward tilting of the stems on the descending flow,the HV system became obvious with the increase of the tilting angle,the vortex volume increased and gradually approached to the column,and the strength of the HV system decreased with the continued tilting of the column after it reaches 90°.The change pattern of the vortex volume with the column tilting angle of HV1 showed a parabolic pattern of increasing first and then decreasing.The maximum value of vortex was 90°>105°>75°>135°>45°>150°.[Conclusion]The synthesis shows that,in the early stage of slope current development,tilting the plant stems can weaken the reverse flow of water at the bottom of the stems to a certain extent,inhibit the generation of downward flow,weaken the structure of horseshoe vortex,and then reduce the erosion of the bed by thin-layer flow,and the greater the degree of tilting of the stems,the better the inhibition effect on soil erosion.关键词
坡面薄层流/倒伏角/流场/马蹄涡系统/PIVKey words
slope thin-layer flow/lodging angle/flow field/horseshoe vortex system/PIV分类
农业科学引用本文复制引用
张迪,张会兰,李峰,谷方正,王铃涵..基于PIV的茎秆倒伏角度对坡面薄层流水动力学特性的影响[J].水土保持学报,2025,39(3):335-344,351,11.基金项目
国家自然科学基金项目(52279056) （52279056）
