Stevens Researcher Nick Parziale Awarded $953K Grant from Office of Naval Research to Study Hypersonic Turbulence
Using the Stevens Shock Tunnel, the project aims to increase understanding of the aerodynamics related to vehicles traveling at supersonic and hypersonic speeds
Nick Parziale, associate professor in the Department of Mechanical Engineering at Stevens Institute of Technology, envisions a world where a flight from Los Angeles to Tokyo that today takes at least 12 hours could be completed in just an hour.
Parziale has devoted his research to supporting that spirit of revolutionary advances in aerodynamics by studying how air moves around vehicles traveling at high speeds. He recently received a four-year, $952,915 Office of Naval Research (ONR) award for his project, “Turbulence Quantities in Supersonic (up to five times the speed of sound) and Hypersonic (five or more times the speed of sound) Flows.”
The ONR grant focuses on the chaos of the turbulent boundary layer, the 0.040-inch flow of gas near a high-speed vehicle.
“The state of the boundary layer can dictate a vehicle’s capability,” Parziale explained. “A vehicle with a turbulent boundary layer has higher drag and heat transfer, so it requires more thrust and more thermal protection. My group studies the transition of the boundary layer from a well-ordered state to a chaotic, turbulent state. We also study the physics of turbulent boundary layers, which is the primary subject of this new ONR grant. We will be making high-quality measurements of the nature of turbulence in supersonic and hypersonic flows, then using that data as a comprehensive reference for high-speed turbulence computations.”
Rather than performing tests in the atmosphere or with computer-simulated models, Parziale is using the 60-foot-long hypersonic Mach 6 Stevens Shock Tunnel that he and his team designed several years ago. Funded by an ONR grant, with additional support from the Air Force Office of Scientific Research (AFOSR), this wind tunnel can generate air flows at six times the speed of sound, and at conditions that duplicate that of flight at an altitude of about 25,000 feet (4.7 miles) with a nozzle exit diameter of 16 inches..
“We have unique testing capabilities here at Stevens. We have the ability to create hypersonic conditions in the shock tunnel at Mach 6, in addition to unique tools to make novel measurements,” Parziale said. “It’s an exciting opportunity to generate and investigate air flows in entirely new ways.”
Because the grant addresses the basic physics of hypersonic turbulence, Parziale and his team are also not using models shaped like aircraft. Instead, a basic flat plate and a hollow cylinder with a flared end will be measured at various angles and speeds as the team collects data on pressure, heat transfer, friction drag and current velocity. The shapes may be simple, but the logistics are demanding.
“These experiments last a small fraction of a second,” Parziale said. “You have to coordinate the timing of a half dozen pieces of equipment to communicate effectively to within 50 billionths of a second — then repeat that 200,000 times per second for the duration of the test. The logistical task is daunting, but so are the fundamental issues associated with making hypersonic fluid mechanics measurements.”
The ONR grant supports two Ph.D. students as research assistants, and undergraduate students will be invited to participate through the department’s summer undergraduate research fellowship, the Stevens Pinnacle Scholars program and the National Science Foundation Research Experiences for Undergraduates (REU) program.
“One of the best parts of this job is working through these issues one-by-one with the students,” Parziale said, “and seeing them go from frustration to elation when their experiment begins to collect new data.”