Passive and Active Control of the Radiated Sound Power from a Submarine Excited by Propeller Forces

From flat-plate flexural vibration and radiated sound power discussed the inherent relationship between panel vibration frequency of distributed mode loudspeaker and geometric parameters, impedance matrix of soundboard and studied the relationship between soundboard structure of polyester foam sandwich panel and distortion of loudspeaker. Experimental results showed that distortion increases as the cell size and compress modulus, cell ratio, cell open ratio and thickness increases, but the sound sensitivity decreases as the compress modulus increases.

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THE USE OF MODAL TAILORING TO MINIMIZE THE RADIATED SOUND POWER OF VIBRATING SHELLS: THEORY AND EXPERIMENT

Journal of Sound and Vibration ◽

10.1006/jsvi.1998.1799 ◽

1998 ◽

Vol 217 (2) ◽

pp. 335-350 ◽

Cited By ~ 29

Author(s):

E.W. Constans ◽

G.H. Koopmann ◽

A.D. Belegundu

Keyword(s):

Sound Power ◽

Radiated Sound ◽

Theory And Experiment ◽

Radiated Sound Power

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Modal Analysis of a Vibrating Plate Considering Internal Damping and Application to the Estimation of Radiated Sound Power. 2nd Report, Estimation of Modal Total Loss Factor and Application to the Estimation of Radiated Sound Power.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C ◽

10.1299/kikaic.60.78 ◽

1994 ◽

Vol 60 (569) ◽

pp. 78-85

Author(s):

Iwao Hayashi ◽

Nobuyuki Iwatsuki ◽

Kyosuke Wakasa

Keyword(s):

Modal Analysis ◽

Loss Factor ◽

Total Loss ◽

Sound Power ◽

Internal Damping ◽

Radiated Sound ◽

Radiated Sound Power ◽

Vibrating Plate

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FE-BE computation of electromagnetic noise of a permanent-magnetic excited synchronous ma-chine considering dynamic rotor eccentricity

MATEC Web of Conferences ◽

10.1051/matecconf/201821118005 ◽

2018 ◽

Vol 211 ◽

pp. 18005

Author(s):

Marcel Clappier ◽

Lothar Gaul

Keyword(s):

Sound Power ◽

Fe Model ◽

Electromagnetic Noise ◽

Structural Dynamic ◽

Magnetic Forces ◽

Rotor Eccentricity ◽

Resonance Frequencies ◽

Radiated Sound ◽

Run Up ◽

Radiated Sound Power

Electromagnetic noise in Electrical Machines (EMs) occurs due to vibrations caused by magnetic forces acting onto rotor and stator surface. This is the dominant source for the considered permanent-magnetic excited synchronous machine in this paper. The radiated electromagnetic noise is sequentially calculated by a Finite Element (FE) and Boundary Element (BE) computation. An electromagnetic FE model is created to determine magnetic forces. Structure-borne sound and rotor dynamics are calculated using a structural dynamic FE model for the EM housing and the rotor. In order to predict resonance frequencies and amplitudes as reliable as possible, it is important to know the direction-dependent stiffness of the laminated rotor stacks and mechanical joints as well as their structural damping. Thereby, the properties of the laminated stack can be determined experimentally by a shear and dilatation test. Mechanical joint properties can be modelled by Thin-Layer Elements (TLEs) and the overall damping by the model of constant hysteretic damping. The radiated sound power is determined by a direct BE computation. The influence of dynamic rotor eccentricity on radiated sound power is examined for a run-up of the EM. All FE models are verified by data from experimental modal analysis.

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Acoustic Radiation Simulation of Marine Sliding-Thrust Bearing Shell Based on SYSNOISE

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.291-294.1961 ◽

2011 ◽

Vol 291-294 ◽

pp. 1961-1964

Author(s):

Guang Liang Zhao

Keyword(s):

Dynamic Analysis ◽

Boundary Element ◽

Thrust Bearing ◽

Acoustic Radiation ◽

Element Model ◽

Sound Power ◽

Supporting Structure ◽

Radiated Sound ◽

The Impact ◽

Radiated Sound Power

This paper takes marine Kingsbury sliding thrust bearing as the research object and conducts the finite element dynamic analysis with the aid of ANSYS software. On this basis, the acoustic boundary element model of a sliding thrust bearing shell is established with the ANSYS dynamic analysis results as the boundary excitation conditions. Besides, the radiated sound power of the shell is calculated by indirect boundary element method in SYNOSISE software. The influence of different condition parameters on the radiated sound power of the shell is perceived through the analysis of several rotation-thrust conditions. As for the special structure of this kind of sliding-thrust bearing, this paper states the impact of the supporting structure performance parameters, the pad number and damp of shell on the shell radiated sound power. The optimized measure for the supporting structure and the plan concerning the pad number’s selection lays the theoretical basis for damping and noise-reducing research on marine sliding-thrust bearing and its rotor system.

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