Confined Radial Buoyant Jet

Abstract

A submerged, negatively buoyant radial jet, discharging horizontally beneath a free surface into water of initially uniform density, was studied experimentally and theoretically. The situation relates to the operation of an ocean thermal energy conversion plant and is an example of buoyancy and confinement offering opposing influences on jet trajectory. For shallow submergence, the jet is attached to the free surface while for large submergence or greater (negative) buoyancy, the jet is detached. An experimental program yielded data on jet trajectory, temperature, velocity and discharge conditions associated with transition between attached and detached regimes. A hysteresis effect was noted as the conditions for attachment and detachment were different. Dimensional analysis yielded a single parameter of primary importance and two parameters of secondary importance in describing jet behavior. An integral jet analysis based on a spreading assumption was successfully adapted to include induced velocity and pressure effects on jet behavior.