含复杂形态柔性植被水流水力特性的试验研究  

Experimental Study on Hydraulic Characteristics of Water Flow with Complex Flexible Vegetation

作　　者：桂婕 王平[1] Gui Jie;Wang Ping(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,北京100083

出　　处：《水动力学研究与进展（A辑）》2023年第6期974-986,共13页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金(52179056);雄安新区科技创新专项任务(2023XAGG0066)。

摘　　要：天然河道植被的复杂形态是影响水流结构和水流阻力的重要因素,对真实植物形态的准确描述有利于合理解释其水流水力特性。该文立足于真实水生植物,利用三种形态的塑料模拟植被(簇生草状型、分枝带叶型和平面单叶型)开展水槽试验,研究了柔性植被复杂形态对水流结构与阻力特性的作用机制,研究发现:①柔性植被复杂形态对水流结构的影响具有明显非均匀性,即叶片分布集中的部分对水流的阻挡作用更大,且植被形态的突变会使水流产生较大的剪切作用,当植被密度增加时该效应表现更明显;②其中,簇生草状植物主导流态为有利于泥沙淤积的内向交互作用流态;平面单叶植物主导流态为有利于泥沙起动与物质运输的外向交互流态;分枝带叶型植物主导流态在较高和较低密度下,为有利于泥沙起动与物质运输的外向交互流态,在中等密度下,为有利于泥沙淤积的内向交互作用流态;③三种类型植被阻力大小规律为:簇生草状>分枝带叶>平面单叶,植被在水流作用下发生弯曲的程度为:平面单叶>簇生草状>分枝带叶。The complex morphology of natural river vegetation is an important factor affecting water flow structure and flow resistance.Accurately describing the plant morphology is beneficial for reasonably explaining the changes in water hydraulic characteristics.In this paper,based on the real aquatic plant,the flume experiments using three forms of plastic simulated vegetation(tufted grass,clustered herbaceous plants,and flat single leaf plants)to study the mechanism of complex forms of flexible vegetation on flow structure and resistance characteristics are carried out.It is found that:①The impact of complex flexible vegetation on water flow structure is significantly non-uniform,that is,the parts with concentrated leaf distribution have a greater blocking effect on water flow,and sudden changes in vegetation morphology can cause significant shear effects on water flow,and this effect is more pronounced when vegetation density increases;②Among them,the dominant flow pattern of clustered herbaceous plants is an inward interactive flow pattern that is conducive to sediment deposition,the dominant flow pattern of flat single leaf plants is an outward interactive flow pattern that is conducive to sediment initiation and material transport,and the dominant flow pattern of branched leaf plants is an outward interactive flow pattern that is conducive to sediment initiation and material transport at higher and lower densities,an inward interactive flow pattern that is favorable for sediment deposition at moderate density;③The resistance of the three types of vegetation follows a pattern of clustered grass>branched belt leaves>flat single leaves.The degree of curvature of vegetation under the action of water flow is planar single leaves>clustered grass>branched belt leaves.

关 键 词：明渠水流 柔性植被 复杂形态 水流结构 阻力特性 

分 类 号：TV131.2[水利工程—水力学及河流动力学]