Effects of cavitation in a nozzle on liquid jet atomization

Abstract

Cavitation in two-dimensional (2D) nozzles and liquid jet in the vicinity of the nozzle exit were visualized using high-speed cameras to investigate the effects of cavitation on liquid jet under various conditions of cavitation and Reynolds numbers σ and Re. Liquid velocity in the nozzle was measured using a laser Doppler velocimetry to examine the effects of cavitation on the flow in the nozzle and liquid jet. As a result, the following conclusions were obtained: (1) cavitation in the nozzles and liquid jet can be classified into the four regimes: (no cavitation, wavy jet), (developing cavitation, wavy jet), (super cavitation, spray) and (hydraulic flip, flipping jet), (2) liquid jet near the nozzle exit depends on cavitation regime, (3) cavitation and liquid jet are not strongly affected by Re but by σ, and (4) strong turbulence induced by the collapse of cavitation clouds near the exit plays an important role in ligament formation.

Fuel property and fuel temperature effects on internal nozzle flow, atomization and cyclic spray fluctuations of a direct injection spark ignition–injector

“…Sou et al 15 investigated the influence of Reynolds numbers (Re = 45,000-76,000) and cavitation numbers (CN = 0.55-1.57) on formation of cavitation zones in the nozzle and the resulting liquid jet by varying the nozzle size, fluid properties and liquid flow rate. The geometric-induced cavitation zones and the shape of the liquid jet at the nozzle exit are not strongly affected by the Reynolds number but by the cavitation number.…”

High-Speed Laser Image Analysis of Plume Angles for Pressurised Metered Dose Inhalers: The Effect of Nozzle Geometry

“…Schematic cavitation flow model for the flat nozzle geometry ( 25 ) On the other hand, the cone and curved cone nozzles contain outer expansion in their geometries. This cone shape will provide regions for vapour recirculation and generates extra pressure on the initial plume after its exit (Fig.…”

Considerations of Impact of Venturi Effect on Mesophilic Digestion

“…This parameter was established on the assumption that total stagnation energy of liquid is e t = p ∞ /ρ in arbitrary stream cross section can be expressed as a sum The simplest way to obtain throttling effect is by creating a plate-shaped element with the orifice. However this kind of device provokes sludge deposits in the hydrodynamical shadow area, and from this practical reason, it was decided to use standard Venturi tube [13][14][15][16].…”