Experimental and numerical simulation of gravity currents on sloping beds

The aim of this paper is the investigation of gravity currents moving on beds with different slopes by both laboratory experiments and numerical simulations. Laboratory experiments are performed by full-depth lock exchange release and an image analysis technique is applied to measure the space-time evolution of the gravity current's profile. A two-layers, 2D, shallow-water model is used to simulate gravity currents. The model takes into account the space-time evolution of free-surface and the mixing due to the gravity current. Entrainment at the interface between the gravity current and the ambient fluid is modeled by a modified Ellison & Turner’s formula (1959). Several tests are run to calibrate an entrainment parameter in order to reproduce gravity currents moving both on a horizontal and upsloping beds. The comparison between numerical and experimental results shows that the developed model is a valid tool to reproduce gravity current’s dynamics.