Self-Destabilizing Mechanism of Circular Liquid Jet

First Report: Capillary Waves Associated with Liquid Jet Destabilization

Abstract

Capillary waves are radiated upstream from the liquid jet tip which contracts under the action of surface tension force from its upstream portion. The possible processes which change the upstream propagating capillary waves to unstable waves moving downstream with the liquid flow are explored on the basis of the one-dimensional governing equations which are derived to describe the temporal surface deformation along the liquid jet. It is found that the reflection of the capillary waves at the nozzle exit, the gas pressure action due to the velocity difference between the ambient gas and the deformed liquid jet and the local destabilization of superposed capillary waves are main candidates responsible for the liquid disintegration involved in turbulent atomization and liquid jet breakup.