Masters Theses

Keywords and Phrases

Effective perceived noise level (EPNL); Eversman code


"A numerical method has been developed in order to study the effect of turbofan inlet acoustic treatment on the resulting cumulative noise heard by observers on the ground. The approach to creating the tool was to combine the capabilities of the NASA-developed Aircraft Noise Prediction Program (ANOPP) with the fan noise propagation and radiation code developed at Missouri University of Science and Technology. ANOPP can be used to predict the noise metrics resulting from a typical commercial aircraft with turbofan engines on several different flight profiles, including takeoff, approach/landing and a steady (constant altitude/airspeed) flyover. These capabilities are valuable for studying the effects of varying the parameters of turbofan acoustic liners on the overall noise footprint of the aircraft during a steady flyover event. The fan noise code includes a model of the two-degree-of-freedom acoustic treatment typical in many turbofan engine inlets and is, thus, appropriate for including the effects of the liner itself as well as the variation of liner parameters in the study. The combination of the two computational schemes results in a tool for predicting not only the effects of including the fan inlet acoustic treatment during a flyover, but also the variation of the geometric parameters describing the acoustic treatment and their associated realistically achievable manufacturing tolerances. This research is also intended to develop the tool through which acoustic liner manufacturers can study the effects of their designs and tolerances on the realized attenuation of cumulative noise that reaches the observer on the ground and is subject to federal aircraft noise regulations"--Abstract, page iii.


Eversman, Walter

Committee Member(s)

Riggins, David W.
Banerjee, Arindam


Mechanical and Aerospace Engineering

Degree Name

M.S. in Aerospace Engineering


Spirit Aerosystems Inc.


Missouri University of Science and Technology

Publication Date

Summer 2012


x, 46 pages

Note about bibliography

Includes bibliographical references (pages 110-114).


© 2012 Devin Kyle Boyle, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Airplanes -- Turbofan engines -- Noise
Noise control -- Mathematical models

Thesis Number

T 10045

Print OCLC #


Electronic OCLC #