Calculation of the Interphase Heat and Mass Transfer in a Nozzle Spray Cone Taking into Account the Drag Crisis and the Heat- and Mass-Transfer Crisis
N. N. Simakov
Abstract
Details of a numerical model and the results of calculation are presented for the interphase heat and mass transfer in the two-phase flow produced by nozzle spraying of a liquid into a gas. The proposed mathematical model is based on the unsteady-state differential equations of flow of a compressible medium, supplemented with the equations of heat and mass transfer from the drops to the gas. Difference analogs of the equations of continuity and motion of the phases are created using the known Lax–Wendroff explicit scheme. The axial and radial profiles of the velocities and temperatures of the drops and the gas in the free nozzle spray cone, and also in the two-phase flow through the cylindrical apparatus, are calculated taking into account the early drag crisis of the drops and the crisis of the heat-and-mass transfer inter the phases, and also the specific features of the turbulent friction in the gas, which were detected in previous experiments. In the calculations, in particular, the dependences of the temperatures of the drops and the gas, averaged over the outlet section of the apparatus, on the gas flow rate through the apparatus are characterized.