Lenka Šroubová

Higher-order finite element modeling and optimization of actuator with non-linear materials

An electromagnetic actuator with nonlinear structural parts is modelled and optimized. The aim of the optimization is to obtain a flat static characteristic and reach the highest possible force acting on its plunger (manufactured of permanent magnet) at the smallest possible dimensions. The solution of the problem is carried out numerically by the professional software package COMSOL Multiphysics fully controlled by a number of special in-house scripts and procedures. First, two deterministic optimization algorithms are applied to evaluate several different actuator configurations and determine the optimal actuator design from the viewpoint of the maximum force acting on its movable part. Then, a genetic algorithm is used for a multiobjective optimization providing the flattest possible static characteristic. The methodology is illustrated by a typical example whose results are discussed.

N-body simulation of electrically charged plastic particles motion in free-fall electrostatic separator

A mathematical model of electrically charged plastic particles movement in the free-fall electrostatic separator is discussed based on the theoretical analysis and experimental observation. The formulated model considers both field-to-particle and also particle-to-particle interactions and takes into account stochastic characteristics of the model parameters. Simulation of particle motion, therefore, represents solution of a coupled problem of electric field and N-body dynamic problem. An adaptive algorithm for simulation of the problem is proposed and finally verified by simulation experiments and also measurement of the separation process on laboratory prototype.

Minimization of force and thermal effects in bus bars

Force and thermal effect in bus-bar systems are investigated. The goal of this research is to find the configuration exhibiting their minimum possible values. The computations are carried out numerically, using the fully adaptive higher-order finite element method. The methodology is illustrated with several examples whose results are discussed.

Electromagnetic field along the power overhead line at point where the line route changes direction

Purpose – High-voltage overhead lines produce low-frequency electromagnetic fields around them. These fields are easy to compute wherever the line route is straight, as opposed to places where its direction is changed. The purpose of this paper is to perform a numerical analysis of an electromagnetic field occurring along a high-voltage overhead line at the places of the changed direction and to compare the results with the exposure limits for low-frequency electromagnetic fields in order to assess their effects on living organisms. Design/methodology/approach – The computation was conducted in the MATLAB SW by means of a combination of integral and differential methods in a three-dimensional (3D) arrangement, taking into account the location and shape of the tower. Special procedures within the MATLAB software had to be coded. Findings – Within the research, the following electromagnetic field quantities were computed: the distribution of electric field strength, magnetic flux density, Poynting vector, e...

Steel buried pipeline influenced power overhead line

The influence of three-phase overhead power lines on parallel steel pipelines is investigated. The principal monitored value is their resistive heating. The computations are realized numerically, by the finite element method. The comparison of adaptive techniques in finite elements methods is shown using software Agros 2D and COMSOL Multiphysics. The methodology is illustrated by two examples whose results are discussed.