It's a sci-fi concept that's at the center of a 25-year exploratory project: building a hypersonic aircraft that takes off from the runway and doesn't need a rest, inspection or repair after it lands – unlike the space shuttle – but can zip back around the world within an hour of landing. University of Cincinnati researchers are developing the validation metrics that could help predict the success or failure of such a model before it is even built, as test data becomes available from component, to sub-system, to the completely assembled air vehicle.

University of Cincinnati Professor Randy Allemang in the Structural Dynamics Research Lab.
Randy Allemang, a UC professor of mechanical engineering and director of the Structural Dynamics Research Lab in the UC College of Engineering and Applied Science (CEAS), has developed a validation metric that involves principal component analysis (PCA) decomposition of simulation and test data to measure the uncertainty in how well the models match with measured data, which will ultimately determine the success in approaching how such a plane could be built. That 25-year exploratory project is led by the U.S. Air Force.

"The very early stages of testing examine the concept of a plane that would fly as much as 10 times the speed of sound, with Mach 5 being the starting point," says Allemang. "In order to be ready to build that airplane, there is a lot of technology that will need to improve over the next 20 years, and there aren't the resources to do the prototype testing like what was done in the space race of the '50s and '60s. So, we need to improve analytical capabilities to better predict what could happen."

Allemang says further testing of the PCA validation metric is expected to be conducted on an aircraft panel later this year by the Structural Sciences Center at the Air Force research labs at Wright-Patterson Air Force Base.