Entraining gravity currents in containers of general cross-section form

Previous research on gravity currents, the flow of a denser fluid through a less dense one, has largely focused on channels with rectangular cross-sections. How do these currents flow through more complex, nonrectangular shapes found in nature, like river estuaries or valleys? A generalized model that accounts for crucial effects of entrainment and drag in channels of various shapes is presented. This model reveals how these factors significantly reduce the current's propagation speed while increasing its height and volume, especially in nonrectangular geometries. This work provides enhanced understanding of these flows, with findings that can be applied to diverse natural and engineered systems.