Aerospace Seminar: Experimental Investigations of Fluid Structure Interactions in Hypersonic Platforms

Seminar Speaker:
Venkat Narayanaswamy, Ph.D.
Associate Professor of Mechanical and Aerospace Engineering at North Carolina State University

Abstract:
My research group focuses on addressing various propulsion and aerodynamics phenomena to achieve ultrafast air mobility and commercial space access. In this talk, I will present our ongoing efforts to investigate the fluid structure interactions in hypersonic platforms. Specifically, the talks explores the dynamics of an impinging shock boundary layer interactions (SBLI) flowfield to a thin panel executing small amplitude elastic oscillations (oscillation amplitude much smaller than the incoming boundary layer thickness as well as panel thickness). This unit problem provides crucial understanding of the genesis of the macro-scale flow response with larger amplitude vibrations and ultimately to feedback coupling between flow and structures. The oblique shock was generated by an 8-degree shock generator placed incident on a Mach 2.5 flow. The shock strength was large enough to generate a nearly two dimensional mean separation and the pulsations of the separated bubble straddled several elastic bending modes of the thin panel. As a critical component of this research, the first ever simultaneous multivariate measurements of panel surface pressure, panel center-span deflection, and off-body velocity field are also presented. Together, these measurements provide comprehensive information on the FSI phenomenon from both aerodynamics and structural dynamics perspectives. Summarily, at the low amplitude panel vibrations, there is no change in the mean separation size, which was confirmed by multiple measurements. Interestingly, the separation shock oscillations appear to pick up some of the panel resonance modes frequencies. Detailed cross-coherence maps at and away from panel modes as well as conditional maps of panel surface pressure reveal further information about how the shock motions can eventually result in macro-scale response.

About the Speaker:
Dr. Venkat Narayanaswamy is an Associate Professor at Mechanical and Aerospace Engineering Department of NCSU, where he has served as a faculty since 2012. He directs a lab that focuses on hypersonic aerodynamics and propulsion related topics and employs several state of the art tools for his research. Dr. Venkat Narayanaswamy received his doctoral degree from The University of Texas at Austin specializing in shock boundary interaction physics and plasma-based control. Subsequently, he pursued a postdoctoral fellowship at The University of Texas at Austin and RWTH Aachen, Germany, before joining NCSU. Dr. Narayanaswamy has authored over 30 journal publications and over 40 articles in peer-reviewed conferences. He has been recognized with numerous research awards and honors including the AFOSR DURIP Award (2018), AFOSR Young Investigator Program Award (2016), Air Force Summer Faculty Fellowship (2016), and North Carolina Space Grant New Investigator Award (2014). He is also an alumni of National Academy of Engineering’s Frontiers of Engineering, Class of 2020.

Hosted by: Dr. Jack McNamara, Professor of Mechanical and Aerospace Engineering at The Ohio State University.