February 22, 2023: Liselle Joseph

February 22, 2023
1:30 p.m.
Room: 310 Kelly Hall
Liselle Joseph, Spectral Sciences, Inc.
Faculty Host: Dr. Bhuvana Srinivasan

"Aerodynamic Considerations for Hypersonic Vehicle Detection"

Abstract:  Hypersonic technology has been around since the 1950s, and intercontinental ballistic missiles have been in military arsenals for decades. However, there has been a clear increase in hypersonic weapons development and testing by US adversarial nations recently, which is a major concern for the US and our allies. The conditions encountered by hypersonic vehicles are quite complex due to the non-linear, strong interaction between the flow-field and vehicle.  Therefore, technology development in this field requires multi-physics approaches that account for the wide range of complex phenomenon occurring simultaneously and at various rates. This includes, but is not limited to, high-temperature gas dynamics including species excitation of internal energy modes and finite-rate gas chemistry, chemical and mechanical response of the vehicle thermal protection system, fluid-structure interactions, turbulence, aero-optical distortions, and electromagnetic signature detection across a wide band of wavelengths. This seminar will discuss some of the aerodynamics which are relevant to detecting a hypersonic vehicle along a typical boost-glide trajectory.  We will focus on how these aerodynamic phenomena play out at such high speeds, and the effect they ultimately have on vehicle detection. We will also examine some of the challenges associated with Computational Fluid Dynamics (CFD) in this regime, and how the simulated flow-field can be used to predict vehicle detection.

Bio:  Dr. Liselle Joseph is currently a Senior Scientist at Spectral Sciences, Inc. (SSI). Her research focuses on modeling the hypersonic flow-field around vehicles using high fidelity Computational Fluid Dynamics (CFD). Her work has ranged from developing methods to predict aero-optical distortions through the hypersonic flow-field, modeling the electromagnetic spectra from the hypersonic flow-field, and modeling ablation and turbulence in the hypersonic flow-field. At SSI, she has been the Principal Investigator on two programs funded by the DoD, and supported several similar initiatives. Before joining SSI in 2020, Dr. Joseph was a Senior Aerospace Engineer working in the Aero/Thermal Fluids organization of Pratt and Whitney. At Pratt and Whitney, Dr. Joseph working primarily on developing new compression system technologies for both commercial and military applications. In addition to working on multiple programs, she is the aerodynamics leader of one program and is deeply engaged in the development of sustainable, forward-facing computing tools and methods.  Dr. Joseph earned B.S. (2011), M.S. (2014) and Ph.D. (2017) degrees in Aerospace Engineering at Virginia Tech, with graduate research focused on the systematic and critical analysis of experimental data by developing novel analysis tools rooted in random data spectral analysis and fundamental aerodynamic principles. In her five years working in Virginia Tech’s world-class Stability Wind Tunnel, she independently led 4 projects, and assisted in several others, funded by the Office of Naval Research, the National Science Foundation, and General Electric Power & Water. Her work is published in notable journals, including the Journal of Fluid Mechanics and JANANF.