Flow Properties of Several Types of Liquid Flows through Micro-Orifices

Abstract

The flow properties of several types of liquid passing through various sizes of micro-orifices were investigated in this paper. The jet thrust and pressure drops were measured for two polyethylene glycol solutions and four surfactant solutions. Different flow properties were found for the various surfactant solutions depending on the charge of the solute. For an anionic surfactant, the results were similar to those for water, whereas in the case of a cationic surfactant, both the jet thrust and pressure decreased greatly in comparison with the other test liquids. Finally, a nonionic surfactant exhibited a steep rise in the pressure drop at a particular value of the Reynolds number. In explaining this behavior, the liquid-solid interface and alignment of the surfactant molecules are considered, and consequently, it is strongly suggested that the elastic stress on elongational flows is a contributing factor. In addition, the decreases in pressure and thrust for polyethylene glycols are attributed to viscoelastic properties, regardless of the molecular weight of PEG.

Flow Properties of Ultra-Fine Bubble Mixtures Passing through Micro-Apertures

“…In previous studies, Hasegawa et al [23] reported the possibility that water flow through a micro-aperture is elastic, but in the case of UFB mixtures containing only air, it is not thought that the results can be explained in terms of elasticity. In research employing Re values similar to those in this study, Ushida et al [24] noted that surfactant molecules behave like polymer chains as a result of electric interactions, and are therefore able to exhibit a phenomenon similar to elasticity. Additionally, compared with the UFB size, the slit width was much larger; the ratio between averaged value of D b and smallest slit width was 2.82 × 10 .…”

Flow Properties of Microbubble/Polyethylene Glycol Mixtures Passing through Orifices and Slits

“…[9][10][11][12][13][14][15] Figure 3 shows the experimental apparatus for measuring pressure drops. The basic setup is the same as that in previous research.…”

“…The basic setup is the same as that in previous research. [9][10][11][12][13][14][15] up to 500 Pa, 10 kPa, and 500 kPa.…”

“…Following previous researches [10][11][12] , elongational stress, the elasticity property under elongational (orifice and slit) flows, was expressed by the reduction in the pressure drops: …”

“…Ouchi et al 8) conducted an experiment using an aqueous solution of cetyltrimethylammonium bromide and sodium salicylate, which form wormlike micelles, and reported on the shear induced structure and instabilities. Ushida et al 9,10) examined the flow properties of several types of surfactants that form spherical micelles, and found a drag reduction in elongational flows. Hasegawa et al 11,12) measured the flow properties and the rheological properties of dilute aqueous solutions of polyethylene oxide.…”