Laboratory experiments investigating the interaction of a lock-exchange dense gravity current and a submerged obstacle with a triangular section have been conducted to determine the influence of the relative obstacle height, i.e. the ratio between the heights of the current and the obstacle, on the dynamics of the overflowing dense current. Experimental measurements were aimed to obtain detailed instantaneous density fields through an image analysis technique based on light attenuation. The dense current is deeply affected by the interaction, depending on the relative obstacle height. When the height of the current approaching the obstacle is small, a lower percentage of overflow propagates downstream and a large reduction in the gravity current velocity is observed. The analysis of the density fields highlights that the formation of a macro vortex downstream of the obstacle is the mechanism responsible for the enhanced dilution of the overflow. Nevertheless, the bulk entrainment parameter is slightly affected by the presence of a bottom obstacle. Results deepen our understanding of the entrainment processes related to the interaction with the obstacle and confirm the role of relevant non-dimensional numbers.

已经进行了研究锁交换密集重力流和具有三角形截面的水下障碍物相互作用的实验室实验，以确定相对障碍物高度，即流与障碍物高度之间的比率，对动力学的影响溢出的密集电流。实验测量旨在通过基于光衰减的图像分析技术获得详细的瞬时密度场。密集电流受相互作用的影响很大，取决于相对障碍物高度。当接近障碍物的水流高度较小时，向下游传播的溢流百分比较低，并且观察到重力流速度大大降低。对密度场的分析强调，在障碍物下游形成的宏观涡流是导致溢流稀释增强的机制。然而，散装夹带参数受底部障碍物的存在轻微影响。结果加深了我们对与障碍物相互作用相关的夹带过程的理解，并确认了相关无量纲数的作用。