Mississippi State University
Janus, Jonathan M.
Date of Degree
Graduate Thesis - Open Access
Master of Science
James Worth Bagley College of Engineering
Department of Aerospace Engineering
Jet noise remains one of the most important problems in the aviation industry, and its reduction is sought in the context of both commercial and military aircraft. In this thesis, an investigation of the jet noise is conducted in terms of the effect of temperature and Mach number on low frequency acoustic spectra. A low-order model derived from the generalized acoustic analogy method via a lowrequency asymptotic approach is utilized, where the mean flow and pertinent statistical quantities are obtained from RANS simulations. The study involves a combination of seven acoustic Mach numbers ranging from 0.3 to 1.5 and five temperature ratios (TR) ranging from 1 to 3. The model is calibrated with existing experimental measurements of a Mach 0.9 and TR = 1 jet. The results show that the sound pressure level increases with the increase in Mach number, and decreases with the decrease in temperature ratios.
Karam, Sofia, "Investigation of Temperature Ratio Effect on the Low-Frequency Acoustic Spectra of Heated Jets" (2017). Theses and Dissertations. 2853.