Ship on-board noise propagation analysis methods

In last 10 years there has been a major development on anti-noise and vibration treatment materials used in shipping industry. Starting from passive elements such as mineral wool, elastic mountings up to active noise reduction systems based on real-time processors. Simultaneously ship-owners demands for silencing their ships has also evolved. Hence, noise limits got more restricted (especially when comfort class is important i.e. passenger ships, yachts, etc). In order to fulfill those demands noise propagation analysis have to be performed. For many years wave propagation model or statistical model has been incorporated for this purpose. Statistical Energy Analysis method has been also used especially for high frequency range. However only in past few years one can analyse complete frequency spectrum using combined FEA/SEA or EFEA method. In this paper review of noise propagation method tools has been presented with given examples and new direction in research and development has been pointed.