Hyperpycnal flows are observed when the density of a fluid entering into a quiescent environment is greater than that of the ambient fluid. This difference can be due to salinity, temperature, concentration, turbidity, or a combination of them. Over a sloping bottom, the inflowing momentum decreases progressively until a critical stage is reached where the inflow plunges underneath the ambient and flows adjacent to the bed as an underflow density current. In the present work, a new equation is proposed in order to predict the critical depth for plunging, i.e., the plunging criterion. It differs from previous studies since it includes the role of the settling velocity and the bed slope. The high spatiotemporal resolution from twelve original numerical simulations allows us to validate the initial hypotheses established, in addition to numerical and experimental data available in the literature, and good agreement is found between them. A negative value for the mixing coefficient was observed for the first time for the hyperpycnal flow in a tilted channel. This indicates that if the settling velocity of the suspended material is high enough, the submerged flow may lose fluid to the environment (detrainment), instead of incorporating it. The proposed plunging criterion may assist in the design of future experimental or numerical works.

当进入静止环境的流体的密度大于周围流体的密度时，就会观察到高密度流。这种差异可能是由于盐度、温度、浓度、浊度或它们的组合造成的。在倾斜的底部上，流入的动量逐渐减小，直到达到临界阶段，在该阶段，流入在周围环境下方下降并作为底流密度流在床附近流动。在目前的工作中，提出了一个新的方程来预测切入的临界深度，即切入准则。它与以前的研究不同，因为它包括沉降速度和床坡度的作用。来自十二个原始数值模拟的高时空分辨率使我们能够验证建立的初始假设，除了文献中可用的数值和实验数据外，它们之间也有很好的一致性。对于倾斜通道中的超重流，首次观察到混合系数的负值。这表明，如果悬浮物质的沉降速度足够高，淹没流可能会将流体流失到环境中（脱附），而不是将其合并。拟议的暴跌标准可能有助于未来实验或数值工作的设计。淹没的流动可能会将流体流失到环境中（排放），而不是将其吸收。拟议的暴跌标准可能有助于未来实验或数值工作的设计。淹没的流动可能会将流体流失到环境中（排放），而不是将其吸收。拟议的暴跌标准可能有助于未来实验或数值工作的设计。