BYU

Abstract by Jacob Ward

Personal Infomation


Presenter's Name

Jacob Ward

Degree Level

Masters

Co-Authors

Kent Gee
J. Micah Downing

Abstract Infomation


Department

Physics and Astronomy

Faculty Advisor

Kent Gee

Title

Spectral comparisons of noise from ground runup and flyover operations of a high-performance military aircraft

Abstract

Prior work has shown differences between ground runup and flyover noise levels for military aircraft [B. O. Reichman et al., AIAA Paper 2018-3614]. This presentation describes a continuation of that effort to better understand spectral differences as a function of propagation distance, angle, and engine power. Acoustical measurements of a high-performance military jet aircraft made during both ground runup and flyover operations are described. The ground runup and flyover spectra show substantial differences in both shape and levels. In particular, more high-frequency energy is seen in the forward direction in the flyover data, which is believed to be from nonlinear propagation. This analysis examines in greater detail the increased nonlinearity in the forward direction, which is important to improved modeling of the noise from these aircraft. [Work supported by AFCEC.]