Analysis of noise sources in the cabin of a passenger aircraft and methods for combating them

Abstract

This paper examined the problem of noise in the aircraft cabin and ways to solve it. Through observations, the following causes of noise were identified: the power plant (acoustic and mechanical vibrations, turbulent boundary layer and others), the location of the engine relative to the airframe, the noise of the propeller (if it is a propeller power plant), the propeller of the power plant itself, the air conditioning system, and so on the same operating device in the cabin. There is a comprehensive way to solve the problem of noise in the aircraft cabin: for aircraft with turbojet engines, measures aimed at changing the design and use of sound- absorbing materials can be effective. For a turboprop aircraft, it is necessary to create low-noise propellers and synchronize the rotation of the propellers. For air conditioning elements, reducing duct and exhaust velocities allows for satisfactory acoustic performance of these sources. The reduction in “cabin noise” is achieved by changing the manufacturing technology of various noisy units. It should be emphasized that the possibility of reduction in the cabin and the aircraft is, in principle, laid down when designing the units and the aircraft as a whole. It is worth noting sound insulation, vibration insulation, as well as the rational location of noisy units, including the power plant, relative to the passenger cabin of the aircraft. From the study on sound insulation, we conclude that it is best to use 2 sound insulation options. Reducing noise is a feasible task and its greatest progress is achieved even at the design stage itself