环境流体密度分层对浊流的流动和沉积的影响

基于雷诺平均的数学模型模拟研究环境流体密度分层与否条件下,2种入流机制的含多粒径颗粒物浊流由斜坡流至水平地形上的流动和沉积。结果表明:突然释放型浊流不论环境流体有无密度分层均在斜坡及水平地形前段形成沉积物波,而环境流体无密度分层的连续入流型浊流未出现波状沉积;自近源地区至远源地区沉积物粒径逐渐减小,但突然释放型浊流在波状沉积位置有大粒径沉积物,连续入流浊流沉积呈现更均匀的由上游至下游的自然粒径分选。

Influence of Density Stratification of Environmental Fluid on the Flow and Deposition of Turbidity Currents

The characteristics of flow and deposition of turbidity currents with multi-size classes of particles under ambient fluid density stratification from a slope flowing to a horizontal flat bed were investigated by a numerical model based on Reynolds averaged model. The results show that with or without ambient fluid density stratification, sediment waves form on the front parts of slope and flat topography under multiple sudden-release events, while no sediment waves observed for multiple steady sustained-inflow turbidity currents on the same topography without ambient fluid density stratification. The particle size of deposit decreases gradually downstream. For sudden-release events, larger particles deposit more around sediment waves, while clearer downstream fining is observed for sustained-inflow turbidity currents.