Effects of Shock-Tube Cleanliness on Slender-Body Hypersonic Instability and Transition Studies at High-Enthalpy
A series of slender-body hypervelocity boundary-layer instability and transition experiments were performed in the Caltech T5 Reflected-Shock Tunnel. During this campaign, it became clear that the condition of the T5 shock tube would significantly affect the consistency of the instability and transition measurements; a regimen of cleaning was iterated on until satisfactory repeatability was achieved. In this work, a description of the cleaning regimen is given. Additionally, boundary-layer instability measurements and a statistical analysis of the boundary-layer transition scatter are presented for experiments before and after cleaning regimen implementation.
© 2015 American Institute of Aeronautics and Astronautics. The authors would like to thank Bahram Valiferdowsi for help running T5 and Ross Wagnild for help with the program to compute the run conditions. This work was an activity that was part of National Center for Hypersonic Laminar-Turbulent Research, sponsored by the "Integrated Theoretical, Computational, and Experimental Studies for Transition Estimation and Control" project, supported by the U.S. Air Force Office of Scientific Research and the National Aeronautics and Space Administration (FA9552-09-1-0341). Additionally, this work was part of the "Transition Delay in Hypervelocity Boundary Layers by Means of CO_2/Acoustic Interactions" project, sponsored by the Air Force Office of Scientific Research (FA9550-10-1-0491). J. S. Jewell received additional support from the National Defense Science and Engineering Graduate Fellowship and the Jack Kent Cooke Foundation.