Spray Sheet Research Articles

An Interferometric Study of the Flow of Thin Liquid Laminae

AbstractAnumber of investigations have been made of the processes of drop formation in sprays, particularly those produced from flat and conical liquid sheels. Some of these studies have been concerned with relatIng the size of the drops to the properlles of the sheet, and measurements have been mode of Its veloCity and thickness in the region of disintegralian. In this paper, on account is given of the way in which interferometry has been utilized to determine the variation of thickness throughout a flat fan spray sheet.

Some aspects of liquid flow through fan spray nozzles

The flow pattern of the liquid sheet produced from a rectangular-orifice fan spray nozzle is investigated with particular emphasis on the manner in which its thickness varies from the orifice to the point of breakdown. The trajectory of its boundaries is analysed on the basis of a simple theory. The results of the study can be summarized as follows : (a) The streamlines of the spray sheet are straight and unaffected by the curved boundary. The liquid velocity along a streamline is constant, everywhere in the sheet and independent of its viscosity. (b) The thickness of the sheet is at any point inversely proportional to its distance from the orifice, and can be expressed, for a given set of operating conditions, by a thickness parameter. (c) At relatively low injection pressures, the thickness parameter for a given nozzle and liquid of low viscosity is found by experiment to be a function of surface tension and a function of ( P ρ) 1 2 /η where P = injection pressure, ρ = density, η = viscosity. At the high injection pressures the thickness parameter is only a function of ( P ρ) 1 2 /η. (d) The trajectory of the sheet is a function of the injection pressure, sheet thickness and surface tension, and independent of liquid density.

The atomization of liquid in a flat spray

The drop-size distribution in flat sprays produced by agricultural nozzles is discussed and an equation has been derived by dimensional analysis relating a mean drop diameter to operating conditions at the nozzle. The equation has been applied to experimental data for agricultural nozzles with satisfactory results. The development of the spray sheet with pressure increase is shown by high-speed photographs