Experimental Rayleigh-Taylor Instability in a Circular Tube

Abstract

The Rayleigh-Taylor instability of an air-water system has been investigated experimentally. The instability was produced by accelerating a slug of water down a vertical circular tube of 6.25 in. inside diameter employing a pressure differential. Accelerations from 3 to 25 times gravitational acceleration with fluid depths from 5 to 20 centimeters were studied. The disturbances first observed were purely axisymmetric with wave numbers corresponding closely to the fastest growing values given by linear theory. Later stages of planform development were characterized by a series of transitions which cannot be predicted by linear theory. These transitions were correlated with disturbance height.