Copyright 2018 by Travis Kocian, Alexander Moyes, Helen Reed, Stuart Craig, William Saric, Steven Schneider, and Joshua Edelman. Published by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. Under the auspices of NATO STO AVT-240: Hypersonic Boundary-Layer Transition Prediction, this paper describes the results of close collaborations among the authors toward the fundamental understanding and modeling of the instabilities associated with three-dimensional boundary layers in hypersonic flight. Specifically, the focus is directed toward the crossflow instability. A common straight circular cone geometry is analyzed for M 5.91-6 and Re 0 9.8-10.1 106 m from both a computational and experimental perspective using methods that are unique to each facility and methodology. Disturbance wavelength and trajectory, surface roughness, and the use of quiet wind tunnels are just a few items found to be key factors in the investigation of the crossflow instability. Quiet tunnels allow experiments to be performed in a disturbance environment comparable to that expected from flight, and the combination of different facilities and computations displays a comprehensive analysis that would be unobtainable from any individual approach alone.
