Analysis of lock-exchange gravity currents over smooth and rough beds
Analysis of lock-exchange gravity currents over smooth and rough beds
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DOI：
10.1080/00221686.2013.798363
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发表时间：
2013-08
影响因子：
2.3
通讯作者：
Helena I. S. Nogueira;C. Adduce;E. Alves;M. Franca
中科院分区：
文献类型：
--
作者：
Helena I. S. Nogueira;C. Adduce;E. Alves;M. Franca
研究了盐水全深度锁释放到淡水箱中产生的重力流，重点研究了锁中盐水混合物的初始密度和床层粗糙度对重力流运动学的影响。分析了当前锋面位置和锋面速度的时间演变，并将其与水流的不同阶段相关联。还评估了当前深度平均密度和当前高度的时空演化。通道床的粗糙度在当前的运动学中起着重要作用，特别是在由于床处的额外阻力而降低前端速度方面。对弗劳德数的分析，通过初始和局部重力减小进行估计，并根据水流的不同长度尺度建立，可以定义当前发展的每个阶段的重要变量和水流动态。
Gravity currents produced by full-depth lock-release of saline water into a fresh water tank are studied focusing on the influence of the initial density of the saline mixture in the lock and the bed roughness on gravity current kinematics. Temporal evolution of the current front position and front velocity are analysed and related to different phases of the current. Time–space evolution of current depth-averaged density and current height are assessed as well. Roughness of the channel bed plays an important role in the current kinematics, particularly in decreasing the front velocity due to extra drag at the bed. The analysis of Froude numbers, estimated with the initial and local reduced gravity and established with different length scales of the current, allow for the definition of the important variables and current dynamics of each phase of the current development.