Flow behaviour of negatively buoyant jets in immiscible ambient fluid

Abstract

In this paper we investigate experimentally the injection of a negatively buoyant jet into a homogenous immiscible ambient fluid. Experiments are carried out by injecting a jet of dyed fresh water through a nozzle in the base of a cylindrical tank containing rapeseed oil. The fountain inlet flow rate and nozzle diameter were varied to cover a wide range of Richardson Failed to parse (syntax error): Ri ( 10^{−4} < Ri < 1.98) , Reynolds $Re(467<Re<5,928)$ and Weber $We(2.40<We<308.56)$ numbers. Based on the $Re,Ri$ and $We$ values for the experiments, we have determined a regime map to define how these values may control the occurrence of the observed flow types. Whereas $Ri$ plays a stronger role when determining the maximum penetration height, the effect of the Reynolds number is stronger predicting the flow behaviour for a specific nozzle diameter and injection velocity.