Low-frequency interior noise in prop-driven aircrafts: Sources and control methodologies

Abstract

Nowadays, noise has turned into one of the most important among the environmental factors on which industry sets down a big part of its efforts and concerns. The recognition of noise as a serious health hazard is a development of modern times. Too much noise obviously impairs our physical and mental existence and therefore it is reasonable to pursue Technology Assessment concerning noisy technologies. The conflicts of interest associated with noise that arise from the operation of airports are well known. Propeller noise is most dominant at low frequencies (below 500 Hz) where traditional passive treatments have only little effect. The many factors contributing to the sound field inside propeller aircraft have led to extensive research directed toward identifying and improving techniques for interior noise reduction.

Analysis of in-flight cabin vibration of a turboprop airplane by proposing a novel noise-tolerant signal decomposition method

“…There are a variety of internal and external vibration sources in turboprop airplanes such as the engines, propellers, aerodynamic wakes and turbulent boundary layers, and aircraft mechanical systems. Some vibration sources such as aerodynamic wakes and aircraft systems produce broadband vibrations, whereas some others such as blade-induced vibration and its harmonics cause vibrational tones (Mattia et al, 2019; Ommi and Azimi, 2017; Wright and Kidner, 2004). The vibrations generated by these sources are extremely nonstationary due to several reasons.…”