Modelling and Developing an Intelligent Road Lighting System Using Power-Line Communication

The development of a suitable system which will control street lighting ballasts depending on traffic flow, communicate data between each street light along the Power-Line and sense passing traffic. This paper offers the methodology of the system, environmental benefits, commercial benefits and safety benefits of such a unique system. It also shows topics that have been researched to date and potential future development paths this research could take

The Boundary Element Method in Acoustics

The boundary element method (BEM) is a powerful tool in computational acoustic analysis. The Boundary Element Method in Acoustics serves as an introduction to the BEM and its application to acoustic problems and goes on to complete the development of computational models. Software implementing the methods is available

East Lancashire Research 2008

East Lancashire Research 200

The Boundary Element Method in Excel for Teaching Vector Calculus and Simulation

This paper discusses the implementation of the boundary element method (BEM) on an Excel spreadsheet and how it can be used in teaching vector calculus and simulation. There are two separate spreadsheets, within which Laplace equation is solved by the BEM in two dimensions (LIBEM2) and axisymmetric three dimensions (LBEMA). The main algorithms are implemented in the associated programming language within Excel, Visual Basic for Applications (VBA). The BEM only requires a boundary mesh and hence it is a relatively accessible method. The BEM in the open spreadsheet environment is demonstrated as being useful as an aid to teaching and learning. The application of the BEM implemented on a spreadsheet for educational purposes in introductory vector calculus and simulation is explored. The development of assignment work is discussed, and sample results from student work are given. The spreadsheets were found to be useful tools in developing the students’ understanding of vector calculus and in simulating heat conduction

Methods for speeding up the Boundary Element Solution of Acoustic Radiation Problems

Methods for speeding up the boundary element solution of acoustic radiation problems are considered. The methods are based on solving the integral equation formulation of Burton and Miller for the exterior Helmholtz equation over a range of frequencies simultaneously. methods for speeding up the computation of the discrete forms of the integral operators and the solution of the linear systems that arise in the boundary element method are considered. A particular implementation of speed up methods is described. Results from the application of this to test problems are given

The computational modelling of acoustic shields by the boundary and shell element method

In this paper a numerical method for the computation of the acoustic field surrounding a set of vibrating bodies and coupled, forced shells (or shields) is introduced. The method is derived through the reformulation of the Helmholtz equation, which governs the acoustic field, as an integral equation termed the boundary and shell integral equation. Collocation is applied to this equation and a method termed the boundary and shell element method (BSEM) results. Modal modelling of the shell is then included to complete the model of the full acoustic-structure system. The method is implemented for general three-dimensional problems in a Fortran subroutine ABSEMGEN. The subroutine is applied to test problems and results are demonstrated

Fortran codes for computing the discrete Helmholtz integral operators

In this paper Fortran subroutines for the evaluation of the discrete form of the Helmholtz integral operators L k, M k, M k t and N k for two-dimensional, three-dimensional and three-dimensional axisymmetric problems are described. The subroutines are useful in the solution of Helmholtz problems via boundary element and related methods. The subroutines have been designed to be easy to use, reliable and efficient. The subroutines are also flexible in that the quadrature rule is defined as a parameter and the library functions (such as the Hankel, exponential and square root functions) are called from external routines. The subroutines are demonstrated on test problems arising from the solution of the Neumann problem exterior to a closed boundary via the Burton and Miller equation

Solution of discontinuous interior Helmholtz problems by the boundary and shell element method

The Helmholtz equation governing an interior domain with shell discontinuities is not efficiently solvable by the traditional boundary element method. In this paper it is shown how the Helmholtz equation can be recast as an integral equation known as the boundary and shell integral equation. The application of collocation to the integral equation gives rise to a method termed the boundary and shell element method. The associated problem of finding the eigenvalues and eigenfunctions of the Helmholtz equation in a discontinuous domain via the same method is also considered. This leads to a non-linear eigenvalue problem. Such a problem may be solved through polynomial interpolation of the matrix components. In this paper methods for solving the Helmholtz equation and the associated eigenvalue problem are implemented and applied to a test problem

A Solution Method for the Generalised Linear Systems of Equations Arising in Direct Boundary Element Methods Applied to Problems with Robin Boundary Conditions

When the direct boundary element method is used to solve problems with a general Robin (or mixed) boundary condition the resulting linear system of equations is not in the standard form. In this paper, a method involving exchanging columns of the matrices within the system is defined. The method is based on the principle of minimising the propagation of error and returns a system in standard form. Implementations of the method are developed in Matlab, Excel-VBA and Fortran. The method is demonstrated through its application to a test linear system and then it is applied within boundary element method test problems