摘要
水库异重流对提高水库运用效益、高效排沙以及延长水库生命周期具有重要意义,是多沙河流水库调水调沙的重要内容.为探究水库异重流运动特征,建立了异重流控制方程,结合有效悬浮功理论与异重流自相似理论,以小浪底水库为对象分析水库异重流运动特征.研究结果表明:小浪底水库异重流运动存在消亡、自悬浮、激励状态.异重流沿程演化存在临界位置x_(0c).在x_(0c)上游,异重流厚度、含沙量与流速对粒径、坡降、阻力系数变化响应较小;异重流厚度在x_(0c)下游随粒径、坡降、阻力系数增加而增加.粒径增大/减小会使异重流从激励状态向消亡/自悬浮状态转变.当坡降大于临界坡降时,异重流向激励状态转变;当阻力系数大于临界阻力系数时,异重流向消亡状态转变,小于临界阻力系数时异重流保持原有状态.随着潜入点处Richardson数减小,异重流厚度在x_(0c)下游增长速率降低、异重流稳定性减弱、异重流向消亡状态转变,在激励状态下异重流流速在x_(0c)下游流速增加.研究成果对揭示水库异重流运动特征提供了理论支持,为多沙河流水库调水调沙期间调度方案制定提供了理论依据.
Turbidity currents in reservoirs are significant for improving reservoir utilization efficiency,efficient sediment discharge,and extending the reservoir lifespan.They are also crucial in water and sediment regulation schemes for sediment-laden rivers.The governing equations for turbidity currents were established and the evolution characteristics of turbidity currents in the Xiaolangdi Reservoir were analyzed through integration of the effective suspension power theory and the self-similarity theory for turbidity currents.The results indicate that,the turbidity current in Xiaolangdi Reservoir exhibits 3 distinct evolutionary states:attenuation,self-suspension,and activation.During its longitudinal evolution,there exists a critical position x_(0c).Upstream of x_(0c),the turbidity current thickness,sediment concentration,and flow velocity exhibit minimal responses to changes in particle sizes,slopes,and resistance coefficients.Downstream of x_(0c),the turbidity current thickness increases rapidly with the rises in particle sizes,slopes,and resistance coefficients.An increase or decrease in particle sizes can cause the turbidity current to transition from the activation state to the attenuation or self-suspension state,respectively.When the slope exceeds the critical value,the turbidity current will transition to the activation state.When the resistance coefficient will surpass the critical resistance coefficient,and the turbidity current will gradually transition to the attenuation state,whereas a resistance coefficient below the critical value will make the turbidity current maintain in its original state.As the Richardson number decreases at the plunging point,the growth rate of the turbidity current thickness downstream of x_(0c) will slow,the stability of the turbidity current will weaken,and the turbidity current will transition to the attenuation state.In the activation state,the flow velocity of the turbidity current will increase downstream of x_(0c).These findings provide a theoretical foundation for understanding the movement characteristics of reservoir turbidity currents and offer theoretical support for developing regulation schemes during water and sediment management in sediment-laden river reservoirs.
作者
李彬
万占伟
高兴
李树森
白玉川
鲁俊
LI Bin;WAN Zhanwei;GAO Xing;LI Shusen;BAI Yuchuan;LU Jun(Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 450003,P.R.China;Key Laboratory of Water Management and Water Security for Yellow River Basin,Ministry of Water Resources,Zhengzhou 450003,P.R.China;Tsinghua University,Beijing 100084,P.R.China;Yellow River Conservancy Commission Henan Hydrological and Water Resources Bureau,Zhengzhou 450003,P.R.China;State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation,Tianjin University,Tianjin 300350,P.R.China)
出处
《应用数学和力学》
北大核心
2025年第9期1218-1232,共15页
Applied Mathematics and Mechanics
基金
“十四五”国家重点研发计划课题(2023YFC3206703)
国家自然科学基金(51979185)
黄委优秀人才科技项目(HQK-202319)。
关键词
水库异重流
小浪底水库
有效悬浮功
自相似
多沙河流
turbidity current
Xiaolangdi Reservoir
sediment effective power
self-similarity
sediment-laden river
