UT researchers secure $17.8M grant for cutting-edge hypersonic wind tunnel

UT researchers secure $17.8M grant for cutting-edge hypersonic wind tunnel
by Clarence Oxford
Los Angeles CA (SPX) Dec 18, 2024

Researchers from the University of Tennessee, Knoxville, have been awarded a $17.8 million grant by the U.S. Air Force to construct a hypersonic wind tunnel at the UT Space Institute in Tullahoma, Tennessee. The facility will test advanced materials, such as high-temperature ceramics, under the extreme conditions of hypersonic flight - speeds exceeding Mach 5, or five times the speed of sound.

This new wind tunnel will be one of only a few globally capable of simulating hypersonic conditions. It will provide critical insights for future hypersonic vehicles like space shuttles, which experience surface temperatures above 2600 F and immense pressures at speeds nearing Mach 25 upon atmospheric reentry. Such conditions pose significant challenges to thermal protection systems (TPS) that shield these vehicles.

"The TPS is not continuous. Every joint between tiles, and even the glue that sticks the TPS to the fuselage, is a weakness," said Jacqueline Johnson, a materials scientist and professor in the Department of Mechanical, Aerospace, and Biomedical Engineering at UTSI. "We have had two glaring examples of what happens when the TPS is weak or damaged in the Challenger and Columbia space shuttle disasters."

Expanding Research Opportunities

In addition to advancing material science, the facility aims to reduce the backlog for hypersonic testing facilities. "We have all these different kinds of wind tunnels that each specialize in examining some aspect of hypersonic flight...but nobody has the capability to replicate full hypersonic flight conditions," said Assistant Professor Mark Gragston.

Gragston emphasized that the new tunnel would bridge this gap, enabling academic researchers to accelerate the development and testing of materials in conditions closer to those encountered in actual hypersonic flight.

The project also seeks to bolster U.S. expertise in extreme engineering environments by training a new workforce. "Developing a capable workforce is a crucial step in improving the scale economy for these materials and is in line with current initiatives led by the government and industry," Gragston said.

Collaboration and Innovation

Led by Johnson and Assistant Professor Damiano Baccarella, an expert in hypersonic aerothermodynamics, the research team includes specialists from UT, the UT Space Institute, and the University of Dayton Research Institute. The group will focus on hypersonic flow modeling, experimental diagnostics, and advanced materials testing.

"This team was carefully chosen to bring different aspects together, and nobody is trying to be the boss," Johnson said. "There's a lot of work to do, and it cannot be done by UTSI alone."

The grant will fund the construction of the tunnel and a unique workflow for testing TPS materials. Unlike current systems, which require expensive full-scale tests, the UTSI facility will incorporate intermediate-scale evaluations to quickly identify viable materials. "If a subpar material fails in a large-scale test, that's a huge waste of money and time," Gragston noted.

Additionally, the project will refine simulations of hypersonic conditions and utilize noninvasive diagnostic tools developed at UT. These tools, including laser-based chemical analysis, will enhance the accuracy of TPS testing and material evaluation.

A Unique Learning Opportunity

The funding also supports graduate students, offering them hands-on experience in hypersonic research. "The students who are around while this is being built, and are helping build it, will have a truly unique opportunity," Gragston said. This experience will position them as leaders in the development of hypersonic facilities and materials.