摘要
为了研究水生植物对水流结构和泥沙淤积的影响,针对不同布置的沉水植物进行33组浑水水槽试验.结果表明,矮株植物区流速冠顶下为二次多项式分布,以上为对数分布;考虑相对株距的影响,建立矮株植物区紊动强度的双高斯垂线分布公式,按该公式计算的流速和紊动强度与实测资料较吻合.高株植物区流速呈“C”型分布,紊动强度以冠顶附近最大.3种株距布置时,混合植物冠顶以下平均流速为无植物时的32.5%~72.3%.提出小弗汝德数(Fr≤0.18)条件下矮株植物区相对淤积增量与水流强度和相对株距的非线性关系.在相同水流和株距下,混合植物淤积量高达无植物时的7倍,高株植物次之,随着株距的减小促淤效果逐渐增强.
Thirty-three sets of flume experiments were conducted under turbid water and submerged vegetation with different arrangements in order to analyze the influence of vegetation on flow structure and sediment deposition.Results showed that the velocity profile was parabola below the canopy of short vegetation while that was logarithmic above it.A bi-Gaussian distribution formula for turbulence intensity in short vegetation zone was established considering plant spacing.The predicted values of velocity and turbulence intensity accorded well with the measured values.Velocity profile is C-type while the largest turbulence is near the canopy in tall vegetation zone.Average velocity below canopy in mixed vegetation with three kinds of plant spacing was 32.5%-72.3%of that without vegetation.The nonlinear relation of relative deposition increment with flow intensity and plant spacing in short vegetation zone was proposed under small Froude number(Fr≤0.18).The deposition in mixed vegetation zone was the largest with 7 times of that without vegetation under the same flow and plant spacing,followed by that in tall vegetation zone.Effects of tall and mixed vegetation on deposition increased with the decrease of plant spacing.
作者
孙志林
郑佳芸
祝丽丽
种琳
刘俊
罗居元
SUN Zhi-lin;ZHENG Jia-yun;ZHU Li-li;CHONG Lin;LIU Jun;LUO Ju-yuan(Ocean College,Zhejiang University,Hangzhou 310058,China)
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2021年第1期71-80,共10页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学基金资助项目(91647209)
三峡后续工作项目(12610100000018J129-06).
关键词
沉水植物
流速分布
紊动强度
泥沙淤积
submerged vegetation
velocity profile
turbulence intensity
sediment deposition
