Experiments on gravity currents produced from full-depth two-layer stratified buoyancy sources propagating in the slumping phase are presented in the paper. The Froude number in the slumping phase, , where is the front velocity, is the average reduced gravity and H is the lock height, is influenced by the density difference ratio, , and the buoyancy distribution parameter, , where , and are the fluid densities in the upper layer, lower layer and ambient environment while and represent the buoyancies in the upper layer and lower layer. The flow morphology of two-layer stratified gravity currents in the slumping phase can be categorized into two different regimes, demarcated by . For , the gravity currents are dominated by the lower layer and the lower layer takes the lead throughout the slumping phase. The Froude number in the slumping phase for increases as decreases from unity. For , the gravity currents are dominated by the upper layer and the upper layer overrides and outruns the lower layer. The Froude number in the slumping phase for decreases as decreases from unity. As , the upper layer and lower layer propagate forward approximately at the same speed and the Froude number in the slumping phase maintains at irrespective of the density difference ratio. For weakly stratified two-layer buoyancy source, , the influence of the buoyancy distribution parameter diminishes and the Froude number in the slumping phase approaches .

中文翻译：

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坍落期两层分层重力流实验

本文介绍了由全深度两层分层浮力源产生的重力流在坍塌阶段传播的实验。坍落阶段的弗劳德数，其中 是前沿速度，是平均折减重力，H 是船闸高度，受密度差比， 和浮力分布参数的影响， ，其中 ，和 是流体密度在上层、下层和周围环境中，而 和 代表上层和下层的浮力。滑塌相中两层分层重力流的流动形态可以分为两种不同的状态，用 划分。对于 ，重力流由下层主导，下层在整个坍塌阶段处于领先地位。坍塌阶段的弗劳德数从统一开始随着减少而增加。对于 ，重力流由上层主导，上层覆盖并超过下层。坍落阶段的弗劳德数随着从统一的减少而减少。由于 ，上层和下层以大致相同的速度向前传播，并且无论密度差比如何，坍落阶段的弗劳德数都保持在。对于弱分层的两层浮力源，浮力分布参数的影响减小，坍落阶段的弗劳德数接近 。坍落阶段的弗劳德数随着从统一的减少而减少。由于 ，上层和下层以大致相同的速度向前传播，并且无论密度差比如何，坍落阶段的弗劳德数都保持在。对于弱分层的两层浮力源，浮力分布参数的影响减小，坍落阶段的弗劳德数接近 。坍落阶段的弗劳德数随着从统一的减少而减少。由于 ，上层和下层以大致相同的速度向前传播，并且无论密度差比如何，坍落阶段的弗劳德数都保持在。对于弱分层的两层浮力源，浮力分布参数的影响减小，坍落阶段的弗劳德数接近 。