Investigation on the Dispersal Characteristics of Liquid Breakup in Vacuum

Abstract

This work presents an experimental and numerical study on the dispersal characteristics of a liquid jet ejecting into vacuum. The liquid breaking is mainly caused by flash evaporation and bubbles expansion. Experiments of liquid dispersing under different conditions show that the superheat degree is the most important parameter influencing the pattern of the breaking liquid. The jet velocity has large influence on the distribution of the particle sizes. Mixing some volatile liquid with nonvolatile liquid can enhance the dispersion of the latter. The Lattice Boltzmann Method is applied to simulate the breakup process of liquid diglycol and the simulations have good agreement with the experimental results.

Spray flash evaporation SFE process: Identification of the driving parameters on evaporation to tune particle size and morphology

“…The second main parameter is the injection pressure PN. Up to a certain value, the rise of the injection pressure results in a decrease of the obtained droplet size [27].…”

“…Some authors reported the effect of a third parameter, the discharge or backpressure PV, on the stability of the jet which decreases by reducing the chamber pressure. Most of the reported studies occur at a discharge pressure corresponding to the ambient pressure and very few studies were carried out under vacuum [27,28]. Table 5 sums up the operating conditions for flash evaporation studied in literature.…”

Features of inviscid fluid microjets outflow into vacuum

“…Thus, in analyzing long-term discharge of liquid microjets into vacuum (a strongly rarefied medium), certain differences were revealed in the processes of discharging both from an aperture and long capillary from those described in literature [9,[13][14][15]. First of all, this is an extreme instability of the flow shape that remains relatively stable in measuring for very short time intervals.…”

Research Progresses of Flash Evaporation in Aerospace Applications

“…Later, Vieira and Simões-Moreira [35] proved this physical model by the experimental method and observed the blocking behavior as well as the existence of the evaporation wave. Meanwhile, many scholars [35][36][37] have carried out abundant experiments on jet flash evaporation under low pressure.…”

“…The liquid flash evaporation has been used in the America-Russian space station. Hence, many scholars have carried out abundant studies in order to protect the safe stable running of air vehicles [37,68]. In this paper, key attentions were paid to applications of flash evaporation, which was not introduced in detail here.…”