Seminar: Streamwise Vortices in a Turbulent Convex Wall Jet

Abstract

Centrifugal instability is known to manifest itself as counter-rotating streamwise vortices in a number of aerodynamic flows. It results when pressure gradient due to streamwise curvature is insufficient to balance centrifugal force of the curving fluid particles. The resulting streamwise vortices cause quicker transition in laminar flows and increased mixing in turbulent flows. Flowing over a convex wall like that of a cylinder, a wall jet is also subject to this instability — streamwise vortices are generated and affect the evolution of the wall jet. In this talk, effect of steady forcing at the jet nozzle on these vortices and their role in separation of the wall jet from the cylinder will be discussed using PIV measurements. Wall jet also exhibits inflectional instability and the interaction between the two instabilities will also be discussed.  

About the speaker

Pandey is a Ph.D. candidate in mechanical and aerospace engineering at The Ohio State University. He has previously worked on dynamic calibration of pressure-sensitive paints and on their application for rotorcraft and bluff body research. He has been working on convex wall jets for the last two years as part of his dissertation research. 

Hosted by Prof. Jim Gregory.