CAREER: Experimental Investigation into the Impact of Incoming Boundary Layer State on the Unsteady Dynamics of a Transverse Jet in a Hypersonic Crossflow

University Of Texas At San Antonio, San Antonio TX

Investigators

Abstract

Hypersonic flight has obvious appeal given the potential to connect people across the globe by reducing international travel times by a factor of 5 or more, enhancing access to space, and strengthening national defense. Traditional aerodynamic control surfaces seen on aircraft like flaps and fins are ineffective at certain speeds and high altitudes owing primarily to the low pressures and densities in the Earth’s upper atmosphere. This necessitates the use of alternative means of vehicle control for hypersonic systems, which generally takes the form of control jets. An improved understanding of the physics of these interactions will also help improve high-speed engine efficiency and reduce their carbon footprint. When fired into a high-speed flow; however, these jets can create massive disturbances in the flowfield that are complex to model. The current lack of proper predictive tools has rendered jet-based control and fuel-injection unreliable, yet little validation-quality experimental data for this fundamental problem exists in the current literature base. This project will address this need by producing validation-quality experimental datasets of jets issuing into a hypersonic crossflow using the Mach 7 wind tunnel facility at The University of Texas at San Antonio. The acquired data will help unravel the complex physics of this critical flow phenomenon and impact future high-speed vehicle design. This research program will be accomplished in three phases: 1) in-depth characterization of the unsteady dynamics of a jet-in-crossflow over a wide high-speed parameter space; 2) comparison of jet-in-crossflow fluid physics to an analogous standing cylinder geometry; 3) investigation of the transient dynamics of the initiation of a jet in a high-speed crossflow. This work will impact hypersonic aerodynamic research by: 1) quantifying unsteady dynamics and surface loads of jet-in-cross-flow interactions for varied incoming boundary layer states and Mach numbers; 2) characterizing the impact of these jet interactions on control moments for a flat plate; 3) generating validation data for model development. This research will also be tightly integrated with educational outreach. Given the diverse population in San Antonio and The University of Texas at San Antonio’s status as a minority-serving institution, this project will serve as a platform to engage a diverse group of students. The ambitious educational activities include the incorporation of research into new courses (>100 students per semester) and design projects through innovative curricula. Internship experiences with local community college partners will support at least three summer students each year. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.