Dynamics of Underwater Gas Blowout in Sonic Regime: Laboratory-Scale Study

Abstract

To understand the dynamics of vigorous gas jets in underwater gas blowouts, we present a laboratory experiment and data analysis to quantify key physical properties of gas jets horizontally discharged through a single nozzle. This study focuses on the sonic regime of the gas jets (the nominal Mach number from 0.8 to 3.34) and quantifies the jet-to-plume transition through observations of jet penetration length, expansion angle, and trajectory of the jets. Jet penetration is found to be scaled with a modified Froude number accounting for the parameters of real gas (density, pressure, and velocity) in the choked sonic flow. The surfacing fountain profiles are measured to connect water surface observation with the source dynamics through a nondimensional scaling using the densimetric Froude number defined at the release point. A robust −3/5 power-law scaling with a modified Weber number is found to well characterize the median bubble diameter for the bubble breakup process in the sonic gas jets.