05-22-2019 | Venkat Narayanaswamy and Pramod Subbareddy: Experimental and Computational Investigations into Supersonic and Hypersonic Viscous Flows

115th NIA CFD Seminar: Experimental and Computational Investigations into Supersonic and Hypersonic Viscous Flows

Topic: Experimental and Computational Investigations into Supersonic and Hypersonic Viscous Flows
Speakers: Venkat Narayanaswamy, Associate Professor, North Carolina State University and Pramod Subbareddy, Assistant Professor, North Carolina State University

Date: Wednesday, May 22, 2019
Time: 10:30am-noon (EDT)
Room: NIA, Room 137


In this talk we provide an overview of the various research activities in the broad area of compressible boundary layers and shock induced separated flows. In the first half, Venkat Narayanaswamy will present the ongoing research activities on shock boundary layer interactions. The focus will be the current investigations into the dominant flow interactions in different flow units spanning near-2D closed separation unit generated by compression ramp through open separation generated by a sharp fin. Particularly, this talk will focus on the sidewall interference effects on compression ramp interactions and will elucidate the mechanisms that drive the separated flow unsteadiness with increasing shock strength. A variety of measurement tools employed to provide a detailed understanding of the on-surface and off-surface flowfield structure will be presented.

In the second half of the talk, Pramod Subbareddy will discuss the recent works in his group. Three main topics to be discussed – (i) Wall-Modeled LES holds the promise of alleviating the high costs of simulating turbulent boundary layers. We will discuss our experience with various approaches to this problem, with focus on high speed flows. (ii) Modern stability analysis tools (resolvent/input-output analysis) have shown great potential for improving our understanding of several aspects of transition, as well as turbulent flow. We will present preliminary work on the development and usage of these methods. (iii) Designing low-dissipation methods for multi-species flow calculations present numerical challenges since preserving scalar boundedness is often problematic (problems show up in the form of temperature overshoots, lack of mass conservation, etc). We will discuss an approach to tacking this problem.

Speaker Bios
Dr. Venkat Narayanaswamy is an Associate Professor at Mechanical and Aerospace Engineering Department of NCSU, where he has served the department since 2012. He directs a lab comprising eight graduate students and four undergraduate students focusing on high-speed aerodynamics/propulsion and energy related topics. 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 25 journal publications and over 25 articles in peer-reviewed conferences. He is 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 NC Space Grant New Investigator Award (2014).

Pramod Subbareddy is an Assistant Professor in the Mechanical and Aerospace Engineering department at North Carolina State University. He received his Ph.D. degree in Aerospace Engineering from the University of Minnesota in 2007 and his B.Tech degree in Aerospace Engineering from the Indian Institute of Technology, Madras, in 1999. He is a co-developer of the US3D computational fluid dynamics code, with a focus on its numerical and turbulence modeling aspects. His research interests lie in the general areas of turbulence modeling, numerical algorithms, flow stability and transition, and more recently, fluid-structure interactions.