Density Currents Experiments: ABSTRACT

Abstract

An extensive series of experiments on density currents of salt water, or muddy water flowing under fresh water, have been performed by engineers. The author has verified some of the results reported by earlier workers. Some new results have been obtained, using the small flume described by Bell (1942). A specific law of saline fronts was described by Keulegan (1958) who found that the movement of the head of a density current surge across a flat bottom could be described (for high Reynolds Numbers) by the equation [EQUATION] where v is the velocity of advance of the head, C is a constant, ^Dgrp is the density difference between the two fluids, ^rgr is the mean density of the two fluids, d is the thickness of the current behind the head of the current, and g is the acceleration due to gravity. The author's experiments reveal a similar law for density currents flowing down a slope, with the exception that C depends on the slope. It is found that the ratio v/u, where u is the average velocity of uniform flow down the same slope (after the passage of the head), also depends on the slope, and is close to unity only for very low slopes. These results may have considerable significance for interpreting the behavior of turbidity currents. End_of_Article - Last_Page 351------------