Prediction of Aircraft Interior Noise Using the Statistical Energy Analysis Method

Abstract

An analytical model is developed to predict the transmission of noise into an airplane interior through the fuselage sidewall by the statistical energy analysis (SEA) method. The fuselage structure is represented as a series of curved, isotropic plates, the isotropic representation resulting from the effects of smearing out the stiffeners. Other complicating effects such as pressurization, acoustic transmission through windows or seal leaks, and aerodynamic excitation are excluded in this effort but could be modeled by these same methods. Evaluation of the model was made using measured full-scale acoustic data from both an adhesively bonded and a mechanically fastened airplane fuselage structure. Reasonable good agreement was obtained between predicted and measured levels in the higher frequencies. Predicted levels were shown to be sensitive to the value chosen for structural loss factor. Comparisons were also made with the measured data with an estimation procedure reported in the literature.