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March 7, 2019: Axisymmetric Inlet/Isolator Shock Train Dynamics and Shock Boundary Layer Interactions

  •  March 7, 2019
  • 4:00 p.m.
  • 110 Holden Hall
  • Dr. Venkat Narayanaswamy, North Carolina State University
  • Faculty Host: Dr. Todd Lowe


Abstract: My research group focuses on niche aerodynamic and combustion related problems in propulsion and energy technologies, which pose signicant bottlenecks in maturing future technologies. We have ongoing projects that contribute towards widening the operating margin of supersonic inlets, developing tactical boost glide missile systems, addressing the aerothermochemical phenomena that control the flame stabilization in clean combustors, and developing new measurement tools that can provide unprecedented insights into combustion processes. This talk will focus on the first item, wherein we develop a new understanding of the shock boundary layer interaction phenomena that occur in axisymmetric internal flows to unravel the inlet unstart physics.

Inlet unstart is an enduring problem that inhibit the scramjet from widening its operation to lower Mach numbers and poses a critical bottleneck during turbo/ram/scram mode transitions. The unstart issue is particularly harsh in axisymmetric inlets where even 3 incidence angle causes the inlet to unstart in prior studies at NASA. We made detailed investigations of model axisymmetric inlet/isolators to unravel how a flow/pressure event gets transmitted across the isolator channel to learn about unstart initiation mechanisms. We further made detailed investigations into the underlying shock boundary layer interaction physics to unravel some of the flow physics that initiate and perpetuate axisymmetric inlet unstart. The findings of these investigations provided a new understanding of the mechanisms that determine the separation scales in axisymmetric internal flows.

Bio: Dr. Venkat Narayanaswamy is an Associate Professor at
Mechical 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 20 journal publications and over 25 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).