Linear stability analysis of a viscous liquid sheet in a high-speed viscous gas
Air-assisted atomizers in which a thin liquid sheet is deformed under the action of a high-speed airflow are extensively used in industrial applications, e.g. in aircraft turbojet injectors. Primary atomization in these devices is a consequence of the onset and growth of instabilities on air-liquid interfaces. Here the authors apply a temporal linear instability analysis to a thin planar liquid sheet flowing between two semi-infinite streams of a high-speed viscous gas. This study includes the full viscous effects both in the liquid and gas basic states and perturbations. The relevant dimensionless parameters entering the nondimensional Orr-Sommerfeld equation and boundary conditions are liquid and gas Reynolds numbers, gas-to-liquid momentum flux ratio, gas-liquid velocity ratio, Weber number, and equivalent gas boundary layer to liquid sheet thickness ratio. The authors present growth rates and temporal frequencies as a function of wave number, varying the above-mentioned dimensionless parameters. Finally, the authors discuss neutral stability curves.
scientific article; zbMATH DE number 1783583