Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Sescu, Adrian

Committee Member

Belk, Davy M.

Committee Member

Janus, J. Mark

Date of Degree

12-14-2018

Document Type

Graduate Thesis - Open Access

Major

Aerospace Engineering

Degree Name

Master of Science

College

James Worth Bagley College of Engineering

Department

Department of Aerospace Engineering

Abstract

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.

URI

https://hdl.handle.net/11668/19637

Comments

cfd||linear stability||computational fluid dynamics||streamwise extent

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