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

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.

ENFORCING RECIPROCITY IN NUMERICAL ANALYSIS OF ACOUSTIC RADIATION MODES AND SOUND POWER EVALUATION

2012 ◽  
Vol 20 (03) ◽  
pp. 1250005 ◽  
Author(s):  
HERWIG PETERS ◽  
NICOLE KESSISSOGLOU ◽  
STEFFEN MARBURG
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Acoustic Radiation ◽  
Sound Power ◽  
Impedance Matrix ◽  
Radiated Sound ◽  
The Asymmetry ◽  
Power Evaluation ◽  
Radiated Sound Power ◽  
Element Method

By identifying the efficiently radiating acoustic radiation modes of a fluid loaded vibrating structure, the storage requirements of the acoustic impedance matrix for calculation of the sound power using the boundary element method can be greatly reduced. In order to compute the acoustic radiation modes, the impedance matrix needs to be symmetric. However, when using the boundary element method, it is often found that the impedance matrix is not symmetric. This paper describes the origin of the asymmetry of the impedance matrix and presents a simple way to generate symmetry. The introduction of additional errors when symmetrizing the impedance matrix must be avoided. An example is used to demonstrate the behavior of the asymmetry and the effect of symmetrization of the impedance matrix on the sound power. The application of the technique presented in this work to compute the radiated sound power of a submerged marine vessel is discussed.

A compact active structural acoustic control method for minimizing radiated sound power

2021 ◽  
Vol 263 (3) ◽  
pp. 3396-3406
Author(s):  
Scott Sommerfeldt
Keyword(s):  
Control Method ◽  
Acoustic Radiation ◽  
Structural Vibration ◽  
Sound Power ◽  
Flat Plates ◽  
Spatial Gradients ◽  
Acoustic Control ◽  
Radiated Sound ◽  
Radiated Sound Power ◽  
Structural Acoustic Control

Active structural acoustic control is an active control method that controls a vibrating structure in a manner that reduces the sound power radiated from the structure. Such methods focus on attenuating some metric that results in attenuated sound power, while not necessarily minimizing the structural vibration. The work reported here outlines the weighted sum of spatial gradients (WSSG) control metric as a method to attenuate structural radiation. The WSSG method utilizes a compact error sensor that is able to measure the acceleration and the acceleration gradients at the sensor location. These vibration signals are combined into the WSSG metric in a manner that is closely related to the radiated sound power, such that minimizing the WSSG also results in a minimization of the sound power. The connection between WSSG and acoustic radiation modes will be highlighted. Computational and experimental results for both flat plates and cylindrical shells will be presented, indicating that the WSSG method can achieve near optimal attenuation of the radiated sound power with a minimum number of sensors.

CAE Technology Applied to Range Hood’s Noise Control and Optimization Design

2011 ◽  
Vol 338 ◽  
pp. 543-546
Author(s):  
Hu Yu ◽  
Hong Hou ◽  
Liang Sun
Keyword(s):  
Sound Pressure Level ◽  
Optimization Design ◽  
Sound Pressure ◽  
Element Model ◽  
Pressure Level ◽  
Sound Power ◽  
Radiated Noise ◽  
Radiated Sound ◽  
Cae Technology ◽  
Radiated Sound Power

In this study we use the CAE technology to compute and reduce the radiated noise of range hood. First, a finite element model of a typical range hood is created using Hypermesh. Then, the surface particle velocity is carried out in Nastran, and the radiated noise is calculated by Sysnoise. Finally, the DOE-based structural optimization is preformed using iSIGHT-FD, in which the sound pressure level at four sensitive points and the radiated sound power are selected as the objective function and the thickness of four panels are adopted as design variable. In addition, the weight of the range hood as a constraint is kept no more than its original weight. As a result, a maximum radiated sound power reduction of 3.66W and a maximum sound pressure level reduction of 4.7 dB are successfully achieved. It shows the CAE technology is a very efficient and effective method for reducing radiated noise.

A method to compute the radiated sound power based on mapped acoustic radiation modes

2014 ◽  
Vol 135 (2) ◽  
pp. 679-692 ◽  
Author(s):  
Haijun Wu ◽  
Weikang Jiang ◽  
Yilin Zhang ◽  
Wenbo Lu
Keyword(s):  
Acoustic Radiation ◽  
Sound Power ◽  
Radiated Sound ◽  
Radiated Sound Power

Application of the Helmholtz Integral in Acoustics

1986 ◽  
Vol 108 (4) ◽  
pp. 447-453 ◽  
Author(s):  
M. A. Latcha ◽  
A. Akay
Keyword(s):  
Acoustic Radiation ◽  
Surface Element ◽  
Sound Power ◽  
Acoustic Response ◽  
Element Size ◽  
Radiated Sound ◽  
Radiated Sound Power ◽  
Helmholtz Integral

The solution of an isoparametric, overdetermined formulation of the Helmholtz Integral is presented and demonstrated in three examples of acoustic radiation from spherical sources. The placement of the interior, overdetermining points is discussed and guidelines concerning surface element size are developed and tested. The total radiated sound power and transient acoustic response of a dilating sphere are computed.

A Study on Relevance between Distortion of Distributed Mode Loudspeaker and Characteristic of Sound Panel

2011 ◽  
Vol 291-294 ◽  
pp. 2105-2110
Author(s):  
Liang Jin Luo
Keyword(s):  
Vibration Frequency ◽  
Sandwich Panel ◽  
Flexural Vibration ◽  
Sound Power ◽  
Impedance Matrix ◽  
Cell Ratio ◽  
Radiated Sound ◽  
Sound Sensitivity ◽  
The Relationship ◽  
Radiated Sound Power

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.

Sign in / Sign up

Export Citation Format

Share Document