Droplet size resulting from breakup of liquid at gas-liquid interfaces of liquid-submerged subsonic and sonic gas jets

Abstract

It has been demonstrated both analytically and experimentally (Chawla 1975a; Bell, Boyce & Collier 1972) that, due to existence of the Kelvin-Helmholtz instability at the gas-liquid interfaces of liquid-submerged subsonic and sonic gas jets, liquid at the interface breaks up and becomes entrained in the form of droplets in these gas jets. The study of this phenomenon has numerous industrial applications. For example, in the study of the fuel-failure propagation potential of fission-gas jet impingement in liquid metal cooled fast breeder reactor subassemblies, the liquid entrainment rate and droplet size control the rate of heat transfer in the impingement area of the fission-gas jet (Chawla 1975b). The study of the rate of entrainment and droplet size at the gas-liquid interface of a sonic gas jet submerged in a liquid is also of interest in the field of boiling water reactor safety (Chawla 1975b) and in a number of chemical-engineering processes. An analysis of the rate of liquid entrainment at the gas-liquid interface of a liquid-submerged sonic gas jet has been presented previously (Chawla 1975b). The purpose of the present note is to obtain the droplet sizes due to breakup of the liquid at the interfaces of subsonic and sonic gas jets submerged in a liquid. The existing correlations (e.g. Hinze 1948, 1955) for droplet size do not explicitly include the effect of Mach number or compressibility of gas stream; the present analysis, however, explicitly obtains this dependence for both subsonic and sonic gas jets.