Author(s): Edward W. G. Skevington; Robert M. Dorrell
Linked Author(s):
Keywords: No Keywords
Abstract: A gravity current is a flow along a horizontal boundary driven by a density difference between the current and the surrounding ambient fluid. Examples include submarine salinity currents, atmospheric cold fronts, turbidity currents, and ventilation flows. Like open channel flows, gravity currents exhibit two flow regimes classified by the motion of long waves: in subcritical flow waves are able to travel both upstream and downstream, that is the waves are faster (in a relative sense) than the current, while in supercritical flow the waves are swept downstream by the current, the current is faster than the waves. In critical flow the upstream directed waves are stationary. Across a stationary hydraulic jump the current slows from supercritical to subcritical, while across a topographic crest a flow may accelerate from subcritical to supercritical. These flow transitions are essential features that need to be identified to understand experimental and environmental flows.
Year: 2024