Front evolution and dynamics of elliptical gravity currents on a uniform slope

Gravity currents are essentially flows driven by the density difference between the fluids. They are relevant in many geophysical, environmental and engineering problems, such as dust storms, snow avalanches and marine oil spillages. Much work has been carried out on planar or circular gravity currents along a horizontal boundary. However, the effects of initial shape of the gravity current and topography can play an important role in many situations. In the present investigation, we report data from direct numerical simulations of elliptical, finite release, Boussinesq gravity currents propagating down a uniform slope. The study comprises a series of simulations of elliptical gravity currents on a range of slope angles (5° ≤ ≤ 20°) at a Reynolds number of 5000. The shape parameters are varied to study the effects of cross-sectional aspect ratio on the dynamics of the gravity current. It is found that the long-time development of the current is influenced by its initial shape at low slope angles ( = 5° and 10°) whereas the long-time dynamics of the gravity currents is relatively insensitive to its initial shape but is dependent on the slope angle. The physical mechanisms governing the pertinent dynamics of the gravity current will be presented.