Propeller Cavitation Effects on Broadband Vessel-Radiated Acoustic Spectra.
Abstract
To gain an understanding of ambient noise in the oceans today, the characteristics of merchant vessel acoustic spectra must be determined. Presently, it is believed that the major source of acoustic intensity emanating from a merchant is propeller noise. Data was gathered from a stationary vessel whose propellers were cavitating to determine exactly how much of the far field spectrum was propeller dominated. Considerations such as propagation delay and multi-path effects had to be dealt with prior to the processing procedure. Digital signal processing techniques along with the coherence function were applied to the gathered data. The resulting coherence values for frequencies of interest to Navy sonar systems (0-500 Hz) were studied and compared to the corresponding signal-to-noise level in the far field spectrum. The coherence accurately displays that, contrary to present belief, propeller cavitation is not the dominant source of merchant vessel acoustic power in the far field over the entire frequency band of interest.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 20, 1983
- Accession Number
- ADA134233
Entities
People
- Daniel N. Dixon
Organizations
- United States Naval Academy