H.C. Lai

Application of the local radial point interpolation method to solve eddy-current problems

This paper introduces the meshless local radial point interpolation method to model eddy-current problems for the first time. The formulation is described and results are compared with those from the ordinary finite-element simulation and the analytical solution

On the validity of two A-/spl psi/ finite element formulations for modelling eddy current problems with velocity

Two finite element implementations for modelling eddy current problems with velocity are examined here. The formulations are based on the A-/spl psi/ representation. In one finite element implementation, the moving current density is represented as a volume integral term. In the other, volume and surface integral terms represent the moving current density. These formulations are applied to a series of rotational velocity test models differing in conductor topology and the results are compared.

Modeling electromagnetic field propagation in eddy-current regions of low conductivity

We propose a finite-element scheme which involves the use of the Lagrangian interface technique to model electromagnetic signal propagation in mixed regions of very low and high conductivity. The method has relevance to modeling underground communications in oil or gas wells. There will be a significant jump in electrical conductivity especially at the interface between the iron and the nonmetallic conductive regions

Optimization of electromagnetic devices using parameterized templates

A parameterization technique for use in optimizing electromagnetic devices is described. The method allows a rapid alteration of an initial template 2-D or 3-D finite element mesh of an electromagnetic device so that design studies or optimization be conveniently carried out. Two case studies are described. The examples consist of the voltage generated by a wound rotor generator and the performance of a Fluxset magnetic field measuring device.

Design of Salient Structures Using Parameterized Finite Element Models

The action of many electrical machines is based on magnetic forces in salient structures. Examples are switched reluctance machines, magnetic bearings etc. The force production behaviour of many of these machines can be approximately described using analytic methods, based for example on simple magnetic circuits and the principal of virtual work. These methods are well known to be very poor where non linearities are involved. Here, we present simple models which can be used in the initial part of a design of many such machines. These models are non linear and are based on parameterized finite element models

Meshless Multiquadric RBF Method Applied to Two-dimensional Boundry Value Problems

Radial basis functions are a powerful interpolation technique that has become increasingly popular as a mesh free tool to solve partial differential equations. In this paper, the meshless multiquadric RBF is used and some of the issues related to its accuracy are investigated