Open Access

ARTICLE

Dynamics of Free Liquid Jets Affected by Obstructions at the Jet Entrance

V. N. Lad¹, Z. V. P. Murthy^1,2

1 Chemical Engineering Department, Sardar Vallabhbhai National Institute of Technology (NIT -Surat), Surat – 395007, Gujarat, India.
2 Corresponding author. Tel.: +91 261 2201648 Fax: +91 261 2227334 E-mail: zvpm@ched.svnit.ac.in, zvpm2000@yahoo.com

Fluid Dynamics & Materials Processing 2015, 11(3), 241-255. https://doi.org/10.3970/fdmp.2015.011.241

Abstract

Free liquid jets are of great technical importance in a variety of applications like ink-jet printing, glass painting, spray coating and metal cutting. Here we consider the changes induced in the dynamics of such jets by the presence of obstructions at the tube exit. Using stainless steel bars of 1.5 mm diameter as obstruction objects and aqueous solutions of glycerol of varying concentrations as working fluids, we performed experiments for different configurations, including a single rod at the centre of the tube exit, two parallel rods equidistant from the centre of the tube, and a 10 mesh screen. Images of the jets coming through such restricted section were captured by high speed camera from two locations. We could observe a morphological change in the cross section of the liquid jet only for jets passing through a tube exit containing only one rod. The maximum expansion ratio of the jet decreased with the concentration of glycerol. Attempts were also made to correlate the characteristic jet diameter ratio with the Weber number. The findings discussed in the present work may provide a new direction for the design of new instruments for the measurement of surface tension or viscosity of liquids.

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