Calculation of Interphase Mass Transfer in a Spray Flow Produced by a Nozzle with Account of Crisis

Abstract

This paper describes the numerical model and the results of calculating the interphase mass transfer in a two-phase flow generated by atomizing a liquid in a gas using a nozzle. The proposed mathematical model is based on differential equations of unsteady flow in a compressible medium, complemented by the equation of mass transfer from gas to droplets. The popular explicit Lax–Wendroff scheme is used for transition to difference analogs of continuity and phase motion equations. Axial profiles of droplet and gas velocities and gas impurity concentrations in a free spray cone are calculated and presented together with radial profiles of impurity concentrations in a two-phase flow through a cylindrical apparatus, taking into account early drag crisis of droplets and crisis of interphase mass transfer, as well as the features of turbulent friction in gas, discovered in previous experiments. The calculation established the dependencies of the gas flow rate, the concentration of gas impurities at the outlet of the apparatus, and the amount of impurities absorbed by the liquid from the height and cross-sectional area of the apparatus.