Some observations in the vortex-turning behaviour of noncircular inclined jets
New, T. H.
Date of Issue2013
School of Mechanical and Aerospace Engineering
An experimental comparison was conducted for Re = 2,500, free elliptic and rectangular jets inclined at 30° and 60° along major or minor planes. Regardless of the jet base geometry, minor-plane inclined jets produced vortex roll-ups that remain inclined. In contrast, major-plane inclined jets produce significantly stronger vortex-roll-up turning behaviour. Interestingly, major-plane inclined rectangular jets exhibit strong vortex-overturning behaviour, where the vortex-roll-up inclination exceeds the 0° incline angle considerably. Vortex-turning extents and rates are compared between major-plane inclined elliptic and rectangular jets here and support present qualitative observations. Closer inspections reveal that the lack of axis-switching phenomenon in major-plane inclined rectangular jets allows vortex-overturning behaviour. In addition, jet centreline deflection is most sensitive in minor-plane inclined jets, where increasing the incline angle leads to a decrease and an increase in the elliptic and rectangular jet deflection, respectively.
DRNTU::Engineering::Aeronautical engineering::Jet propulsion
Experiments in fluids
© 2013 Springer-Verlag Berlin Heidelberg. This is the author created version of a work that has been peer reviewed and accepted for publication by Experiments in Fluids, Springer-Verlag Berlin Heidelberg. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [DOI:http://dx.doi.org/10.1007/s00348-013-1614-3 ].