Martin Rausch

Computer-aided design of clinical magnetic resonance imaging scanners by coupled magnetomechanical-acoustic modeling

This paper reports on an efficient finite-element scheme for computer-aided design of a clinical magnetic resonance imaging (MRI) scanner. The modeling scheme allows the full three-dimensional calculation of the electromagnetic, mechanical, and acoustic fields, including their mutual couplings. The validity of the computer simulations has been verified by appropriate measurements. Applications include the optimization of the gradient coil and the superconducting magnet with respect to eddy-current losses in the cryostat and the emitted noise.

Magnetomechanical field computations of a clinical magnetic resonance imaging (MRI) scanner

In this paper, an efficient magnetomechanical calculation scheme based on the finite element method is presented. This scheme is used for the precise forecast of the dynamical behavior of a clinical magnetic resonance imaging scanner. The validity of the computer simulations has been verified by means of appropriate measurements. Application examples include the optimization of the superconducting magnet regarding the eddy currents and vibrations in its cryostat.

Advanced computer modeling of magnetomechanical transducers and their sound fields

An advanced numerical calculation scheme based on finite and boundary elements as well as multigrid methods is presented. This scheme is used for the precise forecast of the dynamical behavior of magnetomechanical devices, especially sensors and actuators. Application examples include solenoid valves, electromagnetic sources for the generation of acoustic shock waves, magnetic surface acoustic wave (SAW) filters, electrodynamic loudspeakers and electromagnetic acoustic transducers (EMATs).

Numerical modelling of electrodynamic loudspeakers

A new method for the numerical computation of the dynamic behaviour of electro‐dynamic loudspeakers is presented. The numerical scheme, based on the finite element method (FEM), allows the simulation of coupled magnetic, mechanical and acoustic fields. The obtained simulation results are in good agreement with measured data.

Designing electrodynamic loudspeakers by using a new computer modeling scheme

A new technique for the computer modeling of fluid‐loaded magnetomechanical transducers is presented. This numerical technique is based on a finite‐element method (FEM) and allows the precise calculation of the magnetic, mechanical, and acoustic fields, including their couplings. Further on, nonlinear effects in the mechanical and magnetic behavior are considered. Therewith, the complex dynamic behavior of electrodynamic loudspeakers was studied and, furthermore, an appropriate computer‐aided engineering (CAE) environment has been established. This CAE tool allows an optimization of critical parameters, for example: The validity of the computer simulations is verified with the help of appropriate measurements. The calculated and measured values for eigenfrequencies, axial pressure responses, and electrical input impedances are in excellent agreement. The applicability of the presented calculation scheme with respect to the computer‐aided design of moving coil drivers is demonstrated by reporting several p...