Turbulent eddies in a compressible jet in crossflow measured using pulse-burst particle image velocimetry

Journal Article · Fri Jan 01 00:00:00 EST 2016 · Physics of Fluids

DOI:https://doi.org/10.1063/1.4940677· OSTI ID:1235541

Beresh, Steven J. ^[1]; Wagner, Justin L. ^[1]; Henfling, John F. ^[1]; Spillers, Russell Wayne ^[1]; Pruett, Brian Owen Matthew ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Pulse-burst Particle Image Velocimetry(PIV) has been employed to acquire time-resolved data at 25 kHz of a supersonic jet exhausting into a subsonic compressible crossflow. Data were acquired along the windward boundary of the jet shear layer and used to identify turbulenteddies as they convect downstream in the far-field of the interaction. Eddies were found to have a tendency to occur in closely spaced counter-rotating pairs and are routinely observed in the PIV movies, but the variable orientation of these pairs makes them difficult to detect statistically. Correlated counter-rotating vortices are more strongly observed to pass by at a larger spacing, both leading and trailing the reference eddy. This indicates the paired nature of the turbulenteddies and the tendency for these pairs to recur at repeatable spacing. Velocity spectra reveal a peak at a frequency consistent with this larger spacing between shear-layer vortices rotating with identical sign. The spatial scale of these vortices appears similar to previous observations of compressible jets in crossflow. Furthermore,super-sampled velocity spectra to 150 kHz reveal a power-law dependency of –5/3 in the inertial subrange as well as a –1 dependency at lower frequencies attributed to the scales of the dominant shear-layer eddies.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1235541
• Alternate ID(s): OSTI ID: 1236655
• Report Number(s): SAND2016-0287J; PHFLE6; 618414
• Journal Information: Physics of Fluids, Vol. 28, Issue 2; ISSN 1070-6631
• Country of Publication: United States
• Language: English

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