Hypersonics

Today’s geopolitical environment is driving intense focus on developing hypersonic systems that meet U.S. defense and security needs, now and for the foreseeable future. National pursuit of hypersonic systems by government and industry has intensified during the last few years. Hypersonic vehicles can travel more than five times the speed of sound and fly in the upper reaches of the atmosphere, significantly challenging an adversary’s ability to detect, track, target and engage. These systems are a top Department of Defense (DoD) priority to ensure U.S. dominance.

With more than 40 hypersonics researchers and with leading-edge facilities, Purdue is creating America’s hypersonics engineering epicenter. 2021 has brought outstanding strides, including:

Purdue University approval of funding to build the 65,000-square-foot, $41-million Hypersonics and Applied Research Facility (HARF) in the Purdue Aerospace District. HARF will house:

• The world’s first Mach 8 quiet wind tunnel — the fastest such tunnel in the world, supported by $10 million in funding from the Air Force Research Laboratory (AFRL) and scheduled to go online in 2024.
• The HYPULSE reflected shock/expansion tunnel, donated by Northrop Grumman. Slated to become active in 2023, it will be one of the most versatile high-enthalpy (hot hypervelocity flow) facilities in the world.

Announcement of plans to build the first-of-its-kind Hypersonic Ground Test Center (HGTC), in the Purdue Aerospace District. This central shared utility will allow industry partners to test their hypersonic technologies using multiple test cells and laboratories. The HGTC will be operated as a new nonprofit consortium of national defense industry partners, including Rolls-Royce North America, that also will administer the facility.

Separately, last summer, Rolls-Royce announced the single largest research investment in Purdue history, to increase its footprint in the Purdue Aerospace District. The expansion will incorporate new test facilities to develop high-altitude and hybrid-electric engines that will power the next generation of U.S. military aircraft.

Hosting of the two-day Hypersonics Summit 2.0 with the National Defense Industrial Association. The conference brought together all major industry leaders in hypersonics, along with government and academic partners. Keynote speakers were Gen. David D. Thompson (MSAAE’89), vice chief of space operations for U.S. Space Force; Gillian Bussey, director of the Joint Hypersonics Transition Office in the Office of the Under Secretary of Defense for Research and Engineering; and the Hon. Daniel S. Goldin, the longest-serving NASA administrator.

Since 2001, Purdue has been home to the Boeing/AFOSR (Air Force Office of Scientific Research) Mach 6 quiet wind tunnel — the largest active hypersonic quiet wind tunnel in the world. Quiet tunnels create low-disturbance freestream conditions to study different aerodynamic scenarios, such as spacecraft re-entry or missile flight through the atmosphere, as well as replicating unique engine conditions for extremely high-speed propulsion. They provide well-controlled conditions for testing and evaluation for faculty, industry partners, federal agencies, and other stakeholders.

The Mach 8 and HYPULSE tunnels will offer controlled environments to research several facets of high-speed flight. Specifically, the Mach 8 tunnel will more closely simulate low-freestream disturbance levels, and the HYPULSE tunnel will more closely simulate high-temperature flows — both of which are characteristics of hypersonic flight in the atmosphere that are difficult to create on the ground. Collecting data at higher Mach numbers is critical to extending the understanding of flow physics, especially heat transfer and flight control effectiveness, as DoD programs continue working to fly faster and farther.

A $3.2-million, three-year grant from the NASA University Leadership Initiative (ULI) for a project to refine techniques and hardware associated with a particular set of optical and laser sensors that can be used to examine the surfaces and flow of a hypersonic vehicle to help aircraft maintain control in flight. The award is one of five led by university faculty chosen by NASA to explore innovation in aeronautical research areas, including hypersonic flight.

Purdue’s large, interdisciplinary team of hypersonic research experts brings broad, deep experience in basic and applied research for feasibility determination and design of strong, next-generation hypersonic systems. Faculty and students — collaborating with colleagues from universities across the nation — are a powerful brain trust for national teams in solving the most challenging problems through full-scale lab flight tests and simulation models, supported by continuous learning.

Hypersonics graduates of Purdue are well-represented in industry, government and academia — for example, contributing at Sandia National Laboratories, Defense Advanced Research Projects Agency (DARPA), NASA, Johns Hopkins University Applied Physics Laboratory (JHU/APL), and the DoD. In this way, Purdue is helping to develop the next-generation workforce to sustain hypersonics innovation and production for years to come.