Prediction of acoustic radiation from axisymmetric surfaces with arbitrary boundary conditions using the boundary element method on a distributed computing system

2009 ◽  
Vol 125 (3) ◽  
pp. 1374-1383 ◽  
Author(s):  
Louise Wright ◽  
Stephen P. Robinson ◽  
Victor F. Humphrey
Keyword(s):  
Boundary Element Method ◽  
Distributed Computing ◽  
Boundary Conditions ◽  
Boundary Element ◽  
Acoustic Radiation ◽  
Computing System ◽  
Arbitrary Boundary ◽  
Arbitrary Boundary Conditions ◽  
Element Method

Determination of the Free-Field Acoustic Radiation Characteristics of the Vibrating Plate Structures With Arbitrary Boundary Conditions

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Łukasz J. Nowak ◽  
Tomasz G. Zieliński
Keyword(s):  
Boundary Conditions ◽  
Acoustic Radiation ◽  
Free Field ◽  
Computational Time ◽  
Radiation Characteristics ◽  
Plate Structures ◽  
Arbitrary Boundary ◽  
Arbitrary Boundary Conditions ◽  
Element Method ◽  
Vibrating Plate

The paper presents the developed algorithm which implements the indirect variational boundary element method (IVBEM) for computation of the free-field acoustic radiation characteristics of vibrating rectangle-shaped plate structures with arbitrary boundary conditions. In order to significantly reduce the computational time and cost, the algorithm takes advantage of simple geometry of the considered problem and symmetries between the elements. The procedure of determining the distribution of acoustic pressure is illustrated on the example of thin, rectangular plate with a part of one edge clamped and all other edges free. The eigenfrequencies and the corresponding vibrational mode shapes of the plate are computed using the finite element method (FEM). The results of the numerical simulations are compared to the results of the experiments carried out in an anechoic chamber, proving good agreement between the predictions and the observations. The reliability of simulations and high computational efficiency make the developed algorithm a useful tool in analysis of the acoustic radiation characteristics of vibrating plate structures.

Application of the Boundary Element Method and Modal Analysis to Tire Acoustics Problems

1993 ◽  
Vol 21 (2) ◽  
pp. 66-90 ◽  
Author(s):  
Y. Nakajima ◽  
Y. Inoue ◽  
H. Ogawa
Keyword(s):  
Finite Element ◽  
Boundary Element Method ◽  
Boundary Element ◽  
Acoustic Radiation ◽  
Traffic Noise ◽  
Noise Prediction ◽  
Prediction System ◽  
Tire Noise ◽  
Acoustic Contribution ◽  
Element Method

Abstract Road traffic noise needs to be reduced, because traffic volume is increasing every year. The noise generated from a tire is becoming one of the dominant sources in the total traffic noise because the engine noise is constantly being reduced by the vehicle manufacturers. Although the acoustic intensity measurement technology has been enhanced by the recent developments in digital measurement techniques, repetitive measurements are necessary to find effective ways for noise control. Hence, a simulation method to predict generated noise is required to replace the time-consuming experiments. The boundary element method (BEM) is applied to predict the acoustic radiation caused by the vibration of a tire sidewall and a tire noise prediction system is developed. The BEM requires the geometry and the modal characteristics of a tire which are provided by an experiment or the finite element method (FEM). Since the finite element procedure is applied to the prediction of modal characteristics in a tire noise prediction system, the acoustic pressure can be predicted without any measurements. Furthermore, the acoustic contribution analysis obtained from the post-processing of the predicted results is very helpful to know where and how the design change affects the acoustic radiation. The predictability of this system is verified by measurements and the acoustic contribution analysis is applied to tire noise control.

scholarly journals Weak Imposition of Signorini Boundary Conditions on the Boundary Element Method

2020 ◽  
Vol 58 (4) ◽  
pp. 2334-2350
Author(s):  
Erik Burman ◽  
Stefan Frei ◽  
Matthew W. Scroggs
Keyword(s):  
Boundary Element Method ◽  
Boundary Conditions ◽  
Boundary Element ◽  
Signorini Boundary Conditions ◽  
Element Method

A boundary element method for acoustic radiation valid for all wavenumbers

1989 ◽  
Vol 85 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Kenneth A. Cunefare ◽  
Gary Koopmann ◽  
Klaus Brod
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Acoustic Radiation ◽  
Element Method

ON THE JOINT APPLICATION OF THE COLLOCATION BOUNDARY ELEMENT METHOD AND THE FOURIER METHOD FOR SOLVING PROBLEMS OF HEAT CONDUCTION IN FINITE CYLINDERS WITH SMOOTH DIRECTRICES

2021 ◽  
pp. 15-38
Author(s):  
D.Y. Ivanov ◽  
Keyword(s):  
Fourier Series ◽  
Boundary Element Method ◽  
Boundary Conditions ◽  
Boundary Element ◽  
Initial Conditions ◽  
Fourier Method ◽  
Time Interval ◽  
Cylindrical Domain ◽  
Two Dimensional ◽  
Element Method

Here we consider the initial-boundary value problems in a homogeneous cylindrical domain YI Ω ×+ ( Ω+ is an open two-dimensional bounded simply connected domain with a boundary 5 ∂Ω ∈C , 2 \ Ω≡ Ω − + R is the open exterior of the domain Ω+ , [0, ] YI ≡ Y is the height of the cylinder) on a time interval [0, ] TI ≡ T . The initial conditions and the boundary conditions on the bases of the cylinder are zero, and the boundary conditions on the lateral surface of the cylinder are given by the function 1 2 wx x yt ( , , ,) ( 1 2 (, ) x x ∈∂Ω , Y y ∈ I , T t I ∈ ). An approximate solution of such problems is obtained through the combined use of the Fourier method and the collocation boundary element method based on piecewise quadratic interpolation (PQI). The solution to the problem in the cylinder is expanded in a Fourier series in terms of eigenfunctions of the operator 2 By yy ≡ ∂ with the corresponding zero boundary conditions. The coefficients of such a Fourier series are solutions of problems for two-dimensional heat equations 2 2 t ∇ =∂ + u u ku . With a low smoothness of the functions w in the variable y, the weight of solutions at large values of k increases and the accuracy of solving the problem in the cylinder decreases. To maintain accuracy on a uniform grid, the step of discretization of the boundary function w with respect to the variable y is decreased by a factor of j. Here j is an averaged value of the quantity Y k π depending on the function w. In addition, the steps of discretization of functions ( ) 2 exp − τ k with respect to the variable τ in domains τ≤πT k are reduced by a factor of 2 2 k π . The steps in the remaining ranges of values τ and the steps by the other variables remain unchanged. The approximate solutions obtained on the basis of this procedure converge stably to exact solutions in the 2 ( ) LI I Y T × -norm with a cubic velocity uniformly with respect to sets of functions w, bounded by norm of functions with low smoothness in the variable y, uniformly along the length of the generatrix of the cylinder Y , and uniformly in the domain Ω . The latter is also associated with the use of PQI along the curve ∂Ω over the variable 2 2 ρ≡ − r d , which is carried out at small values of r ( d and r are the distances from the observed point of the domain Ω to the boundary ∂Ω and to the current point of integration along ∂Ω , respectively). The theoretical conclusions are confirmed by the results of the numerical solution of the problem in a circular cylinder, where the dependence of the boundary functions w on y is given by the normalized eigenfunctions of the differential operator By which vary in a sufficiently large range of values of k .

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