Mississippi State University
Belk, Davy M.
Janus, J. Mark
Date of Degree
Graduate Thesis - Open Access
Master of Science
James Worth Bagley College of Engineering
Previous experimental and numerical studies showed that two-dimensional roughness elements can stabilize disturbances inside a hypersonic boundary layer, and eventually delay the transition onset. The objective of the thesis is to evaluate the response of disturbances propagating inside a hypersonic boundary layer to various two-dimensional surface deformations of different shapes. The proposed deformations consist of a backward step, forward step, a combination of backward and forward steps, two types of wavy surfaces, surface dips or surface humps. Disturbances inside of a Mach 5.92 flat-plate boundary layer are excited by pulsed or periodic wall blowing and suction at an upstream location. The numerical tools consist of the Navier-Stokes equations in curvilinear coordinates and a linear stability analysis tool. Results show that all types of surface deformations are able to reduce the amplitude of boundary layer disturbances to a certain degree. The amount of reduction in the disturbance energy is related to the type of pressure gradient created by the deformation, adverse or favorable.
Sawaya, Jeremy David, "The Effect of Two-Dimensional Wall Deformations on Hypersonic Boundary Layer Disturbances" (2018). Theses and Dissertations. 4379.