Item Details

Application of Molecular Tagging Velocimetry to Study Laminar-to-Turbulent Transition in Hypersonic Boundary Layers

Bathel, Brett
Thesis/Dissertation; Online
Bathel, Brett
Goyne, Christopher
This dissertation provides a comprehensive summary of quantitative streamwise velocity measurements in hypersonic boundary layers in a large-scale hypersonic test facility. These measurements are used to study the behavior of streamwise velocity in laminar hypersonic boundary layers and hypersonic boundary layers undergoing transition-to-turbulence. These measurements are made with and without the presence of an isolated cylindrical roughness element on a 20° wedge model. This dissertation provides a review of the theory of boundary layer transition-to-turbulence and of laser-induced fluorescence, which is the mechanism used to measure streamwise velocity non-intrusively. In addition to the streamwise velocity data, a comprehensive image processing method and uncertainty analysis method are presented. The studies in this dissertation also detail the development of two fluorescence-based forms of the Molecular Tagging Velocimetry (MTV) technique for use at NASA Langley Research Center. The first is a single-laser excitation technique using fluorescence of nitric oxide (NO). The second is a three-laser technique where nitrogen dioxide (NO2) is dissociated with a high-intensity laser into NO and oxygen (O), with subsequent probing of NO fluorescence. The measurements presented in this dissertation are the first quantitative non-intrusive flowfield velocimetry measurements obtained in NASA Langley Research Center’s 31-Inch Mach 10 Air Tunnel.
University of Virginia, Department of Mechanical and Aerospace Engineering, PHD (Doctor of Philosophy), 2013
Published Date
PHD (Doctor of Philosophy)
Libra ETD Repository
Logo for In CopyrightIn Copyright


Read Online