OPTIMIZATION STUDY AND PANEL PARAMETER STUDY FOR NOISE RADIATION REDUCTION OF AN AIRCRAFT PANEL EXCITED BY TURBULENT FLOW

Résumé

The noise and vibration in an aircraft cabin during cruise conditions is mostly caused by external flow excitations from the turbulent boundary layer (TBL). The TBL causes the fuselage panels on the aircraft to vibrate. These vibrations radiate sound energy in the form of noise. Therefore, it is of great interest to determine which aircraft panel parameter is most sensitive in decreasing the amount of radiated sound power and how to optimize these parameters to reduce the noise into the aircraft cabin. An analytical model was created and validated using Matlab that calculates the acceleration power spectral density, which is proportional to radiated sound power (RSP). A sensitivity study was performed on the panel parameters, to determine the percent change in acceleration power spectral density (PSD), vs. the percent change in seven different panel parameters: panel thickness, material density, panel width and length, Elasticity modulus, Poisson’s ratio, and damping ratio. An analytical method to optimize an aircraft panel is presented, by changing the panel properties, in order to reduce the acceleration PSD of the panel caused by the TBL. It is shown that panel thickness and panel density are the most consistent and sensitive parameters at, reducing the acceleration PSD, at different octave bands in the human hearing range.