A review of flash evaporation phenomena and resulting shock waves

Flash evaporation or flashing is an evaporation phenomenon caused by a sudden pressure drop sufficiently below the saturation pressure. Due to this sudden drop in pressure, the liquid undergoes a quick phase transition and the sensible heat of the liquid converts into latent heat of evaporation. An accidental release of pressurized liquid from supply pipelines or liquid storage tanks can generate a flashing jet with violent phase change. This fast phase change can cause rapid mixture with an oxidant like air and if the liquid is flammable, disastrous effects such as explosions, fires, and damage to industrial equipment can occur. On the other side, flash evaporation can be beneficially employed in industrial applications. It can have a significant effect on the performance of many devices (i.e. injectors and reactors). This work reviews studies devoted to understanding flashing processes. The review includes experimental, theoretical, and numerical studies related to flashing phenomena, their applications and consequences. Furthermore, the review presents shock waves as one of significant consequences that can be produced by flashing evaporation. The understanding of the fluid behavior of the flash evaporation and the resultant shock waves can help to prevent disastrous consequences that may occur due to accidental fluid release as well as can be useful to further develop the phenomena's industrial and technological applications such as utilize resulting shock waves in creating useful compression.