Visualization of coherent structures in turbulent subsonic jet using planar laser induced fluorescence of acetone

Shelar, Vikas M and Hegde, Gopalkrishna M and Umesh, Govindarao and Jagadeesh, Gopalan and Reddy, KPJ (2013) Visualization of coherent structures in turbulent subsonic jet using planar laser induced fluorescence of acetone. In: EUROPEAN PHYSICAL JOURNAL-APPLIED PHYSICS, 62 (3).

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Abstract

In this paper, we present the molecular density distribution measurement in turbulent nitrogen jet (Re approximate to 3 x 10(3)), using acetone as molecular tracer. The tracer was seeded in the nitrogen jet by purging through the liquid acetone at ambient temperature. Planar laser sheet of 266 nm wavelength from frequency quadrupled, Q-switched, Nd:YAG laser was used as an excitation source. Emitted fluorescence images of jet flow field were recorded on CMOS camera. The dependence of planar laser induced fluorescence (PLIF) intensity on acetone vapor density was used to convert PLIF image of nitrogen jet into the density image on pixel-by-pixel basis. Instantaneous quantitative density image of nitrogen jet, seeded with acetone, was obtained. The arrowhead-shaped coherent turbulent structures were observed in the present work. It was found that coherent structures were non-overlapping with separate boundaries. Breaking of coherent structures into turbulence was clearly observed above four times jet width.

Item Type:	Journal Article
Publication:	EUROPEAN PHYSICAL JOURNAL-APPLIED PHYSICS
Publisher:	EDP SCIENCES S A
Additional Information:	Copy right for this article belongs to EDP SCIENCES S A FRANCE.
Department/Centre:	Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering) Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	06 Sep 2013 06:26
Last Modified:	06 Sep 2013 06:26
URI:	http://eprints.iisc.ac.in/id/eprint/47068

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