Ulrich Lüdtke

Numerical simulation of channel induction furnace to investigate frequency-dependent efficiency

Channel induction furnaces are commonly used for heating and melting alloys in the foundry industry worldwide. The melting frequency is the main issue when constructing an efficient channel furnace. This work investigates an efficient frequency for achieving more favorable results in channel induction furnaces through simulation in two-dimensional space using ANSYS Maxwell. Additionally, the best design solution for the inductor profile is also discussed.

Lorentzkraft — Anemometrie für die berührungslose Durchflussmessung von Elektrolyten

Zusammenfassung Der Beitrag beschreibt den experimentellen Aufbau und die ersten Messergebnisse einer neuen Durchflussmesstechnik für schwach leitfähige Fluide mittels Lorentzkraft-Anemometrie, einem berührungslosen Messverfahren, welches schon erfolgreich für gut leitfähige Fluide wie Metallschmelzen eingesetzt wurde. Potentielle Anwendungen sind heiße und chemisch aggressive sowie nicht transparente Flüssigkeiten, da hier verfügbare Durchflussmesstechniken nur bedingt anwendbar sind. Abstract

Computational MHD Part III — Application to Electromagnetic Control of Convective Flows

Convective flow in a liquid metal heated locally at its upper surface and affected by an applied time-dependent magnetic field is investigated. The system under consideration serves as a physical model for the industrial process of electron beam evaporation of liquid metals. In this process, the strong energy input induces strong temperature gradients along the free surface and in the interior of the melt. Thus, the liquid metal is subject to both thermocapillary and natural convection. The vigorous convective motion within the melt leads to highly unwelcome heat losses through the walls of the crucible. The strong convective heat transfer limits the temperature rise in the hot spot and, therefore, the thermodynamic efficiency of the evaporation process. The present paper aims to demonstrate that the melt-flow can be effectively controlled by using external magnetic fields in order to considerably reduce the convective heat losses. As examples, we employ numerical simulations based on the finite element method to study the effects of both a traveling magnetic field and a rotating magnetic field.