AME Seminar: Harshad Kalyankar
Tuesday, March 19, 2024 - 4:00 p.m.
Harshad Kalyankar
PhD Candidate
Aerospace and Mechanical Engineering
University of Arizona
"On the Control of a Leading-Edge Vortex & its Liftoff on a Cranked, Swept Back Wing"
AME Lecture Hall, Room S212 | Zoom Link
Abstract: Leading Edge Vortex (LEV) lift-off process over cranked wings was investigated in UArizona’s low speed wind tunnel (ALSWT). Surface oil flow visualization highlighted the vortex lift-off location at the crank junction of the wing, and its complex interaction with the flow over the outer wing. Smoke flow visualization, with continuous wave laser and a high-speed camera, enabled time-resolved three dimensional mapping of the flow, albeit qualitatively. Snapshot Proper Orthogonal Decomposition (POD) on the smoke flow images unveiled the dynamic behaviour and potential bimodality in the vortex lift-off process. The unsteadiness in the interior of the LEV is generated by a Kelvin-Helmholtz (K-H) type instability, and they seem to persist even after liftoff. This influences or even imposes an initial condition on the new LEV structure that may be generated over the outer wing i.e. outboard of the vortex lift-off location. Such interactions result in pressure oscillations over the outer wing, resulting in buffeting (potentially in flutter). Preliminary attempts were made to control the lift-off process, but better understanding of this flow phenomenon may provide the means to control buffeting and control the pitch departures that plague tailless aircraft designs.
Bio: Harshad Kalyankar is a PhD candidate, working with Dr. Israel Wygnanski, in the low-speed active flow control domain. He received his MS degree in 2019 from The University of Arizona.