Active Control of Engine Vibrations in a Collins Class Submarine

Document type: Researchreports
Author(s): Mathias Winberg, Colin Hansen, Ingvar Claesson, Xun Li
Title: Active Control of Engine Vibrations in a Collins Class Submarine
Series: Research Report
Year: 2003
Issue: 11
ISSN: 1103-1581
Organization: Blekinge Institute of Technology
Department: Department of Telecommunications and Signal Processing (Institutionen för telekommunikation och signalbehandling)
Department of Telecommunications and Signal Processing S-372 25 Ronneby
+46 455 38 50 00
Authors e-mail: mwn@bth.se
Language: English
Abstract: Submarine manufacturers invest considerable effort and money in improving the attenuation of noise radiated by submarines into the water. A number of different noise sources contribute to the total acoustic signature on an advanced submarine, such as the Collins Class.
This report focuses on the problem associated with low order harmonics generated by the main diesel engines, transmitted through the engine mounts into
the hull, and subsequently radiating into the water. The diesel engine mount consists of a two stage isolation system with a large intermediate mass, weighing approximately $500$ kg. Each engine is attached to the hull by eight mounts.
The main intention of the work described here is to experimentally investigate the use of active vibration control to minimize the vibratory energy of the intermediate mass in all six degrees of freedom, thereby also minimizing the vibratory energy transmitted to the hull. This approach involves the use of seven inertial actuators, mounted on the intermediate mass, to produce the cancelling vibration field.
A test rig, similar to one of the diesel engine mounts on the actual submarine, was constructed in the laboratory at The University of Adelaide and used for the real-time active control experiments described here. Several different set-ups were evaluated using primary vibrations with the same absolute levels and frequency content as measured on board a Collins class submarine. The controller used in the real-time experiments is based on the filtered X-LMS algorithm, which is a feed-forward algorithm working in the time domain.

It is demonstrated here that active vibration control of the intermediate mass of the existing diesel engine mounts is a practical way of reducing the 1.0, 1.5 and 2.0 engine order components in the noise spectrum radiated as a result of vibration transmission through the engine mounts.
Subject: Signal Processing\Active Noise and Vibration Control
Signal Processing\General
Mechanical Engineering\Structural Mechanics
Keywords: Submarine, active vibration vontrol, noise
URN: urn:nbn:se:bth-00239
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