A Case Study of Statistical Energy Analysis: The Police Launch Deodar II

Eric Wester

New Zealand Acoustics, 16(2), pp.29- 33 . (2003).

Statistical Energy Analysis (SEA) is a method which allows the prediction of audio frequency sound or vibration levels in acoustically complex structures such as buildings and vehicles [1,2]. Although SEA is used widely in automobile, aerospace and marine industries overseas, its potential has been little exploited in New Zealand. Industrial Research Limited is currently involved in developing improved statistical modelling methods and in exploring the possible benefits of SEA for New Zealand industry. As part of this ongoing research, a study was undertaken to demonstrate the use of SEA in analysing engine noise on board the police launch Deodar II. A simple SEA model comprising nine subsystems was developed using nominal estimates of structural properties. With this model, and with measurements of the vibrational and acoustic powers input by the engines, predictions were made of sound pressure levels in key acoustic spaces which compare favourably with measured levels.