229 citations · 1.5k across the 32 of their papers we have counts for
32 papers
Coils in thermomagnetic harvesters -- a comparative study
Aske Chris Nilsson, Andrea Roberto Insinga, Salvatore De Angelis +2
Thermomagnetic generators (TMGs) are devices that convert waste heat to electricity through a change in magnetization of a solid material. This causes a changing flux through a coi…
Magnetic levitation by rotation
Joachim Marco Hermansen, Frederik Laust Durhuus, Cathrine Frandsen +3
A permanent magnet can be levitated simply by placing it in the vicinity of another permanent magnet that rotates in the order of 200 Hz. This surprising effect can be easily repro…
Extraordinary magnetometry -- a review on extraordinary magnetoresistance
Thierry Desire Pomar, Ricci Erlandsen, Bowen Zhou +3
Extraordinary magnetoresistance (EMR) is a geometric magnetoresistance effect occurring in hybrid devices consisting of a high-mobility material joined by a metal. The change in re…
MagTense: a micromagnetic framework using the analytical demagnetization tensor
R. Bjørk, E. B. Poulsen, K. K. Nielsen +1
We present the open source micromagnetic framework, MagTense, which utilizes a novel discretization approach of rectangular cuboid or tetrahedron geometry "tiles" to analytically c…
The magnetic field from a homogeneously magnetized cylindrical tile
K. K. Nielsen, R. Bjørk
The magnetic field of a homogeneously magnetized cylindrical tile geometry, i.e. an angular section of a finite hollow cylinder, is found. The field is expressed as the product bet…
The stray- and demagnetizing field from a homogeneously magnetized tetrahedron
Kaspar K. Nielsen, Andrea R. Insinga, Rasmus Bjørk
The stray- and demagnetization tensor field for a homogeneously magnetized tetrahedron is found analytically. The tetrahedron is a special case of four triangular faces with consta…
The demagnetization factor for randomly packed spheroidal particles
R. Bjørk, Z. Zhou
We investigate if the demagnetization factor for a randomly packed powder of magnetic spheroidal particles depend on the shape of the spheroidal particles and what the internal var…
A topology optimized switchable permanent magnet system
R. Bjørk, A. R. Insinga
The design of a magnetic field source that can switch from a high field to a low field configuration by rotation by of a set of iron pieces is investigated using topolog…
The maximum theoretical performance of unconcentrated solar photovoltaic and thermoelectric generator systems
Rasmus Bjørk, Kaspar K. Nielsen
The maximum efficiency for photovoltaic (PV) and thermoelectric generator (TEG) systems without concentration is investigated. Both a combined system where the TEG is mounted direc…
The magnetic properties of the hollow cylindrical ideal remanence magnet
R. Bjørk
We consider the magnetic properties of the hollow cylindrical ideal remanence magnet. This magnet is the cylindrical permanent magnet that generates a uniform field in the cylinder…
Topology optimized permanent magnet systems
R. Bjørk, C. R. H. Bahl, A. R. Insinga
Topology optimization of permanent magnet systems consisting of permanent magnets, high permeability iron and air is presented. An implementation of topology optimization for magne…
An analytical model for the influence of contact resistance on thermoelectric efficiency
R. Bjørk
An analytical model is presented that can account for both electrical and hot and cold thermal contact resistances when calculating the efficiency of a thermoelectric generator. Th…
A thermoelectric power generating heat exchanger: Part I - Experimental realization
R. Bjørk, A. Sarhadi, N. Pryds +2
An experimental realization of a heat exchanger with commercial thermoelectric generators (TEGs) is presented. The power producing capabilities as a function of flow rate and tempe…
The lifetime cost of a magnetic refrigerator
R. Bjørk, C. R. H. Bahl, K. K. Nielsen
The total cost of a 25 W average load magnetic refrigerator using commercial grade Gd is calculated using a numerical model. The price of magnetocaloric material, magnet material a…
The performance of a combined solar photovoltaic (PV) and thermoelectric generator (TEG) system
R. Bjørk, K. K. Nielsen
The performance of a combined solar photovoltaic (PV) and thermoelectric generator (TEG) system is examined using an analytical model for four different types of commercial PVs and…
The universal influence of contact resistance on the efficiency of a thermoelectric generator
R. Bjørk
The influence of electrical and thermal contact resistance on the efficiency of a segmented thermoelectric generator is investigated. We consider 12 different segmented -legs an…
The efficiency and the demagnetization field of a general Halbach cylinder
R. Bjørk, A. Smith, C. R. H. Bahl
The maximum magnetic efficiency of a general multipole Halbach cylinder of order is found as function of . The efficiency is shown to decrease for increasing absolute value…
Metamaterial anisotropic flux concentrators and magnetic arrays
R. Bjørk, A. Smith, C. R. H. Bahl
A metamaterial magnetic flux concentrator is investigated in detail in combination with a Halbach cylinder of infinite length. A general analytical solution to the field is determi…
Determining the minimum mass and cost of a magnetic refrigerator
R. Bjørk, A. Smith, C. R. H. Bahl +1
An expression is determined for the mass of the magnet and magnetocaloric material needed for a magnetic refrigerator and these are determined using numerical modeling for both par…
The influence of the magnetic field on the performance of an active magnetic regenerator (AMR)
R. Bjørk, K. Engelbrecht
The influence of the time variation of the magnetic field, termed the magnetic field profile, on the performance of a magnetocaloric refrigeration device using the active magnetic…
Comparison of adjustable permanent magnetic field sources
R. Bjørk, C. R. H. Bahl, A. Smith +1
A permanent magnet assembly in which the flux density can be altered by a mechanical operation is often significantly smaller than comparable electromagnets and also requires no el…
Improving magnet designs with high and low field regions
R. Bjørk, C. R. H. Bahl, A. Smith +1
A general scheme for increasing the difference in magnetic flux density between a high and a low magnetic field region by removing unnecessary magnet material is presented. This is…
Magnetocaloric properties of LaFeCoSi and commercial grade Gd
R. Bjørk, C. R. H. Bahl, M. Katter
The magnetocaloric properties of three samples of LaFeCoSi have been measured and compared to measurements of commercial grade Gd. The samples have (x=0.86, y=1.…
An optimized magnet for magnetic refrigeration
R. Bjørk, C. R. H. Bahl, A. Smith +2
A magnet designed for use in a magnetic refrigeration device is presented. The magnet is designed by applying two general schemes for improving a magnet design to a concentric Halb…