Penetrating Behavior of a Single Particle Injected into Liquid

Abstract

The penetrating behavior of a single particle impinged on liquid surface has been studied with cold model experiments.
The velocity of a polystyrene particle at impact on distilled water or glycerin liquid was obtained by detectors consisted of laser diode photo sensors. The behavior of the particle, entrained gas bubbles and liquid flow were observed by using a high speed video and camera and analyzed by a mathematical model.
At impact of the particle on liquid surface, a cavity was formed and gas was entrained as a columnar bubble, when the particle impact velocity (V_po) exceeded a critical velocity.
Although the penetrating length of the particle (L_p) increased with increasing V_po, the rate of increase of L_p gradually decreases with increasing V_po.
A mathematical model was developed to predict how the initial kinetic energy of the particle was distributed and consumed by several energy dissipation mechanisms.
It was inferred that most of the kinetic energy was consumed as dissipation works, mainly spitting and heat generation in a higher region of V_po and hence the attainment of a higher particle velocity could not be an effective means to increase penetration length into the liquid. The effect of reduction of the apparent liquid density by increasing gas holdup in the liquid with entrained gas or gas jet was discussed as an effective way to obtain deep penetration of powders into the liquid.