Maximum electromagnetic drag configurations for a translating conducting cylinder with distant magnetic dipoles. - In: Journal of engineering mathematics, ISSN 1573-2703, Bd. 108 (2018), 1, S. 123-141
We report a semianalytic and numerical investigation of the maximal induced Lorentz force on an electrically conducting cylinder in translation along its axis that is caused by the presence of multiple distant magnetic dipoles. The problem is motivated by Lorentz force velocimetry, where induction creates a drag force on a magnet system placed next to a conducting flow. The magnetic field should maximize this drag force, which is usually quite small. Our approach is based on a long-wave theory developed for a single distant magnetic dipole. We determine the optimal orientations of the dipole moments providing the strongest Lorentz force for different dipole configurations using numerical optimization methods. Different constraints are considered for dipoles arranged on a concentric circle in a plane perpendicular to the cylinder axis. In this case, the quadratic form for the force in terms of the dipole moments can be obtained analytically, and it resembles the expression of the energy in a classical spin model. When all dipoles are equal and their positions on the circle are not constrained, the maximal force results when all dipoles are gathered in one point with all dipole moments pointing in radial direction. When the dipoles are equal and have equidistant spacing on the circle, we find that the optimal orientations of the dipole moments approach a limiting distribution. It differs from the so-called Halbach distribution that provides a uniform magnetic field in the cross section of the cylinder. The corresponding force is about 10% larger than that for the Halbach distribution but 60% smaller than for the unconstrained dipole positions. With the so-called spherical constraint for a classical spin model, the maximal force can be found from the eigenvalues of the coefficient matrix. It is typically 10% larger than the maximal force for equal dipoles because the constraint is weaker. We also study equal and evenly spaced dipoles along one or two lines parallel to the cylinder axis. The patterns of optimal magnetic moment orientations are fairly similar for different dipole numbers when the inter-dipole distance is within a certain interval. This behavior can be explained by reference to the magnetic field distribution of a single distant dipole on the cylinder axis.
https://doi.org/10.1007/s10665-017-9916-8
Mathematik in der Basic Engineering School - ein Praxisbeispiel der Lehrformate Just-in-Time Teaching und Gruppenarbeit mit Bearbeitungsstreifen. - In: Digitalisierung in der Techniklehre, (2017), S. 137-142
Towards energy consumption prediction with safety margins for multicopter systems. - In: Proceedings of the 11th EAI International Conference on Performance Evaluation Methodologies and Tools, ISBN 978-1-4503-6346-4, (2017), S. 227-228
Fast abstract
https://doi.org/10.1145/3150928.3150964
Constructing universal, non-asymptotic confidence sets for intrinsic means on the circle. - In: Geometric Science of Information, (2017), S. 477-485
https://doi.org/10.1007/978-3-319-68445-1_56
On quadratic stage costs for mobile robots in model predictive control. - In: Proceedings in applied mathematics and mechanics, ISSN 1617-7061, Bd. 17 (2017), 1, S. 825-826
https://doi.org/10.1002/pamm.201710380
Prevention of solidification cracking during pulsed laser beam welding. - In: Proceedings in applied mathematics and mechanics, ISSN 1617-7061, Bd. 17 (2017), 1, S. 405-406
https://doi.org/10.1002/pamm.201710172
A new bound for the distance to singularity of a regular matrix pencil. - In: Proceedings in applied mathematics and mechanics, ISSN 1617-7061, Bd. 17 (2017), 1, S. 863-864
https://doi.org/10.1002/pamm.201710399
A new method for network redesign via rank one updates. - In: Proceedings in applied mathematics and mechanics, ISSN 1617-7061, Bd. 17 (2017), 1, S. 857-858
https://doi.org/10.1002/pamm.201710396
An estimate on the non-real spectrum of a singular indefinite Sturm-Liouville operator. - In: Proceedings in applied mathematics and mechanics, ISSN 1617-7061, Bd. 17 (2017), 1, S. 859-860
https://doi.org/10.1002/pamm.201710397