Improved Model for the Penetration of Liquid Jets in Subsonic Crossflows

Abstract

A theoretical model for the penetration of a liquid jet in subsonic gaseous crossflow is developed. The model allows for the deformation of the jet cross section from circular to elliptic shapes along its path. A force balance analysis on an elliptical liquid element is performed. Aerodynamic, viscous, and surface tension forces are considered counting for the nonlinear terms at large deformations. The effect of mass shedding is also included in the model. This effect changes the jet trajectory and deformation at higher Weber numbers. In addition, the drag coefficients of elliptical cylindrical elements with different aspect ratios are calculated numerically for a range of Reynolds numbers. It is observed that the drag coefficient of the cylindrical element changes considerably with Reynolds number and the jet deformation. The change in the drag force considerably affects the jet deflection in the gas stream. Results show that the liquid-to-gas momentum ratio is not the only governing parameter in predicting the jet trajectory. Gas Weber number, rate of mass shedding from the jet, jet cross-sectional deformation, variation in the drag coefficient, and variation in the liquid and gas properties all affect the jet penetration.