Airplane interior noise modeling using Statistical Energy Analysis approach

Abstract

Airplane interior broadband noise during the cruise condition is considered to be dominated by the Turbulent Boundary Layer (TBL). The noise prediction model is an important tool which enable engineers to assess various design modifications for noise control. A mathematical model is developed based on the Statistical Energy Analysis (SEA) technique to evaluate design options for interior TBL noise control of the Boeing 737 airplane. The primary frequency range of interest for this model is from 500 Hz to 4000 Hz, which is critical for the speech intelligibility. The predicted cabin noise is within 3-5 dB of the measured noise levels over most of the one-third octave bands. The predicted noise source ranking of the various interior floor and trim panels is similar to the measured noise source ranking. Various design modifications are simulated and compared to the measured data. penalty is the goal for the design team. To effectively reduce cabin noise, the noise sources must be identified and ranked. There are various noise sources for commercial jet airplane - TBL, engine, environmental control system (ECS) and auxiliary equipment, etc.. Among them, TBL is the dominant noise source during the cruise condition, especially in the Speech Interference Level (SIL) frequency range, which includes three octave bands centered on the frequencies 1000,200O and 4000 Hz. This paper deals with a mathematical prediction model based on the Statistical Energy Analysis (SEA) approach to predict the cabin noise generated by the TBL in the 500 to 4000 Hz, l/3 octave band frequency range.