Please use this identifier to cite or link to this item: https://doi.org/10.1007/s00348-003-0733-7
Title: A flow field study of an elliptic jet in cross flow using DPIV technique
Authors: New, T.H. 
Lim, T.T. 
Luo, S.C. 
Issue Date: Apr-2004
Source: New, T.H., Lim, T.T., Luo, S.C. (2004-04). A flow field study of an elliptic jet in cross flow using DPIV technique. Experiments in Fluids 36 (4) : 604-618. ScholarBank@NUS Repository. https://doi.org/10.1007/s00348-003-0733-7
Abstract: The digital particle image velocimetry (DPIV) technique has been used to investigate the flow fields of an elliptic jet in cross flow (EJICF). Two different jet orientations are considered; one with the major axis of the ellipse aligned with the cross flow (henceforth referred to as a low aspect ratio (AR) jet), and the other with the major axis normal to the cross flow (henceforth referred to as a high aspect ratio jet). Results show that the vortex-pairing phenomenon is prevalent in the low aspect ratio jet when the velocity ratio (VR)≥3, and is absent in the high aspect ratio jet regardless of the velocity ratio. The presence of vortex pairing leads to a substantial increase in the leading-edge peak vorticity compared to the lee-side vorticity, which suggests that vortex pairing may play an important role in the entrainment of ambient fluid into the jet body, at least in the near-field region. In the absence of vortex pairing, both the leading-edge and the lee-side peak vorticity increase monotonically with velocity ratio regardless of the aspect ratio. Moreover, time-averaged velocity fields for both AR=0.5 and AR=2 jets reveal the existence of an "unstable focus" (UF) downstream of the jet, at least for VR≥2. The strength and the location of this focus is a function of both the velocity ratio and aspect ratio. In addition, time-averaged vorticity fields show a consistently higher peak-averaged vorticity in the low aspect ratio jet than in the high aspect ratio jet. This behavior could be due to a higher curvature of the vortex filament facing the cross flow in the low aspect ratio jet, which through mutual interaction may lead to higher vortex stretching, and therefore higher peak-averaged vorticity.
Source Title: Experiments in Fluids
URI: http://scholarbank.nus.edu.sg/handle/10635/54157
ISSN: 07234864
DOI: 10.1007/s00348-003-0733-7
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

SCOPUSTM   
Citations

23
checked on Dec 14, 2017

WEB OF SCIENCETM
Citations

21
checked on Nov 19, 2017

Page view(s)

44
checked on Dec 10, 2017

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.