Electronic Theses and Dissertations

Date of Award

2012

Document Type

Dissertation

Degree Name

M.S. in Engineering Science

First Advisor

Nathan E. Murray

Second Advisor

James P. Chambers

Third Advisor

Arunachalam Rajendran

Abstract

A NACA 0018 airfoil model with a 3-inch chord was mounted into the trisonic wind tunnel at the National Center for Physical Acoustics at the University of Mississippi. Tunnel runs were conducted with the angle of incidence increasing from 0 degrees to 6 degrees at 1 degree increments, while the Mach number was held steady at 0.73. High-speed schlieren images were recorded at a sample rate of 4,000 Hz. A Matlab code was developed to display the spatial power spectral density distribution in the region of the shock. This code calculated the frequency spectrum at regular points along the range of shock motion and plotted the spatial distribution of frequency spectra across all the points. This identified the location of the high-amplitude frequencies, which indicated the precise range of the shock motion as well as its dominant oscillation frequency. It was found that, for each degree increase, the frequency of oscillations increased by approximately 10.8 Hz. This is equivalent to a reduced frequency increase of 0.0205 per degree.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.