Advisor

Sescu, Adrian

Committee Member

Belk, Davy M.

Committee Member

Janus, J. Mark

Date of Degree

1-1-2018

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

The development of the so-called Görtler vortices in boundary layer flows over a concave surface leads to strong velocity gradients in both wall-normal and spanwise directions. This determines the flow structures to become more prone to secondary instabilities, which prompt to an early transition from laminar to turbulent flow, ultimately increasing the frictional drag. It is possible to circumvent these secondary instabilities by means of passive or active flow control strategies, with sensors and actuators implemented at the wall. In this thesis, the effect of wall cooling and heating on Görtler vortices developing in supersonic and hypersonic boundary layers is investigated from a numerical point of view. The wall temperature is imposed through a ramping function that decreases or increases an upstream base wall temperature in the streamwise direction. The results show that this type of wall cooling or heating has a mild (adverse) effect on the vortex energy, and a more considerable (but beneficial) effect on the wall shear stress.

URI

https://hdl.handle.net/11668/18719

Comments

wall cooling and heating||Görtler vortices

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