Spatial Distribution Of Current Density Research Articles

Experimental study and optimization of flow field structures in proton exchange membrane fuel cell under different anode modes

As one of the critical components in the proton exchange membrane fuel cell (PEMFC), the flow field is crucial to the improvement of cell performance. However, the current research on flow field structure lacks consideration of the influence of different anode modes, which makes the existing flow field structure rules have limitations in the practical application of PEMFC. In this paper, the PEMFC characteristics of parallel flow field, S-shaped flow field, multi-serpentine flow field and single-serpentine flow field at the cathode side are compared experimentally in the dead-end anode (DEA) mode and hydrogen circulation anode (HCA) mode, respectively. Especially, the spatial current density distribution and parasitic power of different flow field structures are measured. The results show that the performance trends of different flow field structures change with the DEA and HCA anode modes. In DEA mode, the PEMFC is prone to flooding, and the flow field with high gas velocity in the channel has better drainage ability, which can obtain higher cell performance. The HCA mode is helpful for the discharge of water in the PEMFC, which effectively alleviates the adverse impact of water accumulation on the overall performance, and the mass transport ability of the flow field structure plays a leading role in the cell performance improvement. In addition, although the high gas flow velocity has better drainage ability in the flow field, it may lead to a decrease in the current density distribution uniformity and PEMFC net output power density. Based on the comprehensive consideration of the experimental results, the multi-serpentine flow field is more suitable for DEA mode, and the S-shaped flow field is more suitable for HCA mode.

Recent progress on the J-TEXT three-wave polarimeter-interferometer

The J-TEXT three-wave polarimeter-interferometer system (POLARIS), which measures time-space distribution of electron density and current density, has been optimized with both the optical system and the equilibrium reconstruction method. The phase resolution of a Faraday rotation angle has been improved from 0.1 to 0.06 degree in chords from –0.18 to 0.18 m (plasma minor radius), and the sawtooth oscillation behavior has been detected by Faraday rotation angle measurement. By combining the POLARIS measured data and the equilibrium and fitting code (EFIT), an upgraded equilibrium reconstruction method has been developed, which provides a more accurate temporal and spatial distribution of current density and electron density. By means of the optimized POLARIS and improved equilibrium reconstruction, variations of profiles with increasing density have been carried out, under both Ohmic and electron cyclotron resonance heating discharges.

Electro-thermal mapping of polymer electrolyte membrane fuel cells with a fractal flow-field

Electro-thermal maps of a polymer electrolyte membrane fuel cell (PEMFC) show the spatial distribution of current density and temperature, which is useful to evaluate their performance. Here, electro-thermal mapping is carried out for the first time on a PEMFC with a fractal cathode flow-field, the design of which emulates the efficient, scalable air transport inside the lungs. Such maps are compared with those of a conventional single-serpentine flow-field PEMFC. Each cell’s performance is characterised by analysing the surface distribution of current density and temperature at different reactant relative humidity (RH) and cell voltage. Relationships are shown between segment current densities and surface temperatures, and between reactant relative humidity and cell operating conditions. The cells with a fractal flow-field deliver better electrochemical performance and exhibit more homogeneous current distributions compared to those with a single-serpentine flow-field, in which the current distribution is non-uniform due to cell flooding. The surface temperatures are higher in cells with a fractal flow-field than in those with a single-serpentine flow-field, consistent with the observed cell performances. In addition, electrochemical impedance spectroscopy characterisation indicates flooding in the single-serpentine cells, but not in the fractal cells.

Localization of Current Flow in Thermophotovoltaic Converters Based on InAsSbP/InAs Double Heterostructures

The electrical performance of thermophotovoltaic converters with a flip-chip design based on p-InAsSbP/n-InAs/n-InAsSbP double heterostructures with the substrate completely or partially removed is examined. The influence of resistance of different parts of the structure on the spatial distribution of current density in the active region is revealed, and the conditions for maximizing the efficiency of photocurrent collection and minimizing confluence are determined.

Numerical simulation of multiple-current-pulse dielectric barrier discharge with ring electrodes in helium at atmospheric pressure

A two-dimensional fluid model was used to investigate the characteristics of a multiple-current-pulse dielectric barrier discharge (DBD) equipped with ring electrodes in helium at atmospheric pressure. The simulation results show that the discharge at peak moment follows the Townsend mode in the DBD with two current pulses in each half cycle. However, when there are three or four current pulses in each half cycle, the discharge mode at the first current peak transforms to the glow mode. Additionally, for the first and third current pulse, the breakdown first occurs in the radial center of the ring electrodes. But for the discharge in the second and fourth current pulse, it ignites from the periphery of the ring electrodes. Moreover, the discharge structure, i.e., the radial spatial distributions of current density, electron density, and electric field at peak moments, shows a feature of alternation between (1) higher current density, electron density, and electric field locating in the radial center of ring electrodes (center-advantage) and (2) higher current density, electron density, and electric field locating in the periphery of ring electrodes (periphery-advantage). This behavior is attributed to the fact that non-uniform surface charge accumulation during the previous discharge has different effects on the electric field in the gas gap in the subsequent discharge.

Study of plasma equilibrium reconstruction on HL-2A

An equilibrium reconstruction code is a basic tool for determining the plasma position, boundary, shape and current density profile in a tokamak discharge. The equilibrium reconstruction code CPF has been written to make these calculations. It uses a polynomial to describe the spatial distribution of current density. The coefficients of the polynomial are determined by the best least squares fit to the internal and external magnetic measurement data. A finite difference method is used to solve the Grad-Shafranov equation. The equilibrium magnetic surfaces satisfying the convergence criterion is obtained by Picard iteration. The CPF equilibrium reconstruction is also checked by comparing to results obtained by the equilibrium code SWEQU. The CPF code is stable and has been used for several years.

Методика автоматизированного измерения пространственных распределений плотности тока технологических электронных пучков

The importance of developing an automated technique for measuring spatial current density distributions of process electron beams is shown. It has been proven that immediate methods based on directly measuring the electron beam current components are of the main interest for constructing monitoring and control systems in electron beam-based process installations, because it is only these methods that can provide reliable information about the spatial distribution of current density. Experimental investigations of spatial current density distributions for electron beams with power capacities up to 6 kW have been carried out. The distributions obtained by the probe method are analyzed, and their deviations from the normal distribution function and axial symmetry are revealed. The limitations of the probe method based on the heat flux density and beam power are determined, and an express method for measuring the current density radial distribution over the electron beam cross section is proposed, which is based on using the direct edge method and on numerically processing the time dependences of the current. A scheme for quantifying the radial distribution of the electron beam current density is given. The possibility of applying the proposed technique for measuring the characteristics of beams with a power density up to 1.8∙104 W/cm2 using a copper collector has been experimentally confirmed. It is shown that the developed technique is necessary for mathematically reconstructing the current density volume distribution using the basic principles of electronic optics.

The Effect of Membrane Casting Irregularities on Initial Fuel Cell Performance

The polymer electrolyte membrane fuel cell (PEMFC) is a clean alternative to petroleum-based technologies such as the internal combustion engine (ICE). In order to be competitive with the ICE in transportation applications, fuel cell systems must have less than a 10% performance loss after 5,000 hours of operation while reaching cost targets of $40/kW [1,2]. The membrane electrode assembly (MEA), a proton conducting polymer electrolyte membrane (PEM) with attached platinum-containing catalyst layers and gas diffusion layers (GDLs), may possess non-uniformities in any of its constituent components, which could lead to performance losses [3,4]. This work studies a subset of casting irregularities located within the PEM to understand their potential impacts on PEMFC initial performance. If the MEA experiences statistically significant lower initial performance as a result of a casting irregularity, then this irregularity should be classified as a defect. Classification of irregularities as defects will ultimately assist the industry by developing threshold detection limits for in-line quality control diagnostics. Membrane material was cast on a web-line operating within and at the boundaries of the process window by controlling process parameters such as slot and coating gap, flow rate, and substrate speed. The resulting membrane material was either pristine or contained air bubbles, cracks, and contamination, ranging from 0.6 to 3 mm. Gas-diffusion electrodes (GDEs) were fabricated using an ultrasonic spray system. The active area and nominal loading of these GDEs were 50 cm2 and 0.2/0.2 mg Pt/cm2, respectively. MEAs were assembled in the cell by placing a sheet of fabricated membrane material in between two pristine GDEs. Operating conditions for all samples were Tcell: 80°C, anode/cathode relative humidity (RH) at 32/32 and 100/50%, 1.5/2 stoichiometric flow rates of H2/Air, and 150/150 kPa backpressure. Voltage controlled polarization (VI) curves were conducted using a 121 channel segmented fuel cell system. To quantify performance impacts the VI performance of the MEAs containing casting irregularities was subtracted from that of pristine reference MEAs. Thermal imaging was performed subsequent to the performance experiments to map hydrogen crossover to spatial performance [5]. Figure A shows initial VI curves performed at 32/32% RH for four pristine reference samples as well as two samples with casting irregularities. The VI curve data indicate that the samples with irregularities have statistically lower OCV values than the pristine samples. Figure B illustrates the experimental method using GT118 as a representative sample. Prior to the experiment the morphology and size of the casting irregularities were determined using optical microscopy. Sample GT118 contained two air bubbles with sizes of approximately 660 and 1416 µm as shown on the left of Figure B. Then spatial current density distributions were measured with the segmented cell to determine to what extent the casting irregularities caused localized performance losses. The red regions in the spatial current density distribution, shown in the center of Figure B, indicated the lowest local performances in the cell. Subsequent to the performance experiment, a spatial thermal imaging diagnostic was applied to determine regions of increased hydrogen crossover. In the thermal imaging map for GT118 as shown on the right of Figure B, the red boxes indicate air bubble locations and the white regions denote areas of increased hydrogen crossover. These data show the correlation between casting irregularity location, local performance decrease, and increased local hydrogen crossover. In this presentation, we will discuss the impacts of the various casting irregularities in the membrane, and how certain experimental methodologies can be potentially used as defect classification tools. References Marcinkoski, Jason et al. “Fuel Cell System Cost – 2015”. September 30, 2015.James, Brian et al. “Mass Production Cost Estimation of Direct H2 PEM Fuel Cell Systems for Transportation Applications: 2015 Update”. December 2015.Kundu, S., et al. Journal of Power Sources 157.2 (2006): 650-656.Benchmarking and Best Practices Center of Excellence. Manufacturing Fuel Cell Manhattan Project, November 2011 Bender, Guido, et al. Journal of Power Sources 253 (2014): 224-229. Figure 1

Experimental and numerical investigations of the Laplacian and Poissonian field in asymmetric multiple-electrode systems for electrostatic separation processes

Abstract The paper presents an experimental measurements and numerical computations of the electric field in Laplacian field model as well as Poissonian field model for various asymmetric multiple-electrode configurations prepared to electrostatic separation processes. The asymmetric multiple-electrode systems utilize additional cylindrical rods and/or L-plates connected at constant or floating potential, as in practical applications. The geometries include a cluster of spherical/cylindrical conducting particles uniformly distributed and simultaneously in contact with the ground plate. The charge simulation method integrated with genetic algorithm and method of characteristics is employed for numerical computation and analysis of the electric field in the presented models. Neglecting Deutch’s assumption, the numerical technique is applied to solve Laplace's equation or Poisson's equation with the current-continuity relation. Influence of the cluster of spherical/cylindrical particles on the electric field distribution on the ground plate surface, and its acquired charged, is established. I-V characteristics and the spatial distributions of current density and electric field are evaluated and assessed. The experimental results were found to be in a good agreement with analytical values.

Effect of Exchange Current Density on Current Distribution at Planar-Type SOFC Anodes

Introduction It has been reported for SOFC systems that high electrical efficiency of more than 70-80% could be achieved theoretically in a recent study [1]. However, their electrochemical performance would become lower due to an increase in ohmic and nonohmic resistances and possible fuel starvation. From these reasons, it is desired to develop a simulation technique for visualizing various phenomena in fuel cells. Here, we focus on numerical analysis on electrode kinetics. Since exchange current density is an important phenomenological parameter in considering electrochemical reaction kinetics at an SOFC electrode and in simulating the performance, the exchange current density of methane-fueled pre-reformed SOFC anodes was measured and compared with that of hydrogen-based fuel. Furthermore, the spatial distribution of current density was simulated for given average current density in case anode exchange current density i0 is either constant or variable. Experiment In this study, electrolyte-supported cells Ni-ScSZ/ScSZ/LSM-ScSZ (ScSZ:10mol%Sc2O3- 1mol%CeO2-89mol% ZrO2) were used. The electrode area was 8×8mm2 for i0 measurements. Pt mesh was used as a current collector. In this study, by changing operation temperature, fuel utilization (Uf), and steam-to-carbon ratio (S/C), anode overvoltage was measured at each (average) current density (0.25, 0.3, 0.35, and 0.4 cm2) for methane-fueled pre-reformed SOFCs by the current interrupt method. The anode exchange current density was then derived from the current density and anode overvoltage values. Results and discussion Anode exchange current density for hydrogen-fueled SOFCs may be described by Eq. (I) after Hosoi et al. [2]. Anode exchange current density could also be described by Eq. (II) in case vacant surface adsorption sites are predominant [2,3]. Figure 1(a) shows experimental values derived for the pre-reformed fuel in this study. The values derived from Eq. (i) are also shown with solid lines in Fig. 1(a) and (b), while the values derived from Eq. (II) are shown with dashed lines in Fig. 1(b). All these figures indicate gradual decrease in anode exchange current density in the high fuel utilization (Uf) region. i0,a = 3.5・exp(-6.2×104[Jmol-1] / RT)・(PH2 / PH2,ref)0.41・(PH2O/PH2O,ref)0.4 Eq. (I) i0,a = a’・exp(b’ [Jmol-1] /RT)・PH2 0.5 ・PH2O 0.5 Eq. (II) 3D-numerical simulation has been made using the software COMSOL to derive 2D current density of the cell shown in Fig. 1(c). Current density distribution for various average current densities is derived as a function of Uf and shown in Figs. 1(d) and 1(e) for constant i0 and variable i0 , respectively. While Fig. 1(d) suggests continuous decrease in current density from inlet to outlet, Fig. 1(e) suggests almost constant current density near the inlet and its gradual decrease near the outlet. The tendency of the latter is rather consistent with the dependence of anode exchange current density as a function of Uf in Figs. 1(a) and 1(b) for hydrogen-based fuels. Figure 1

A new modified-serpentine flow field for application in high temperature polymer electrolyte fuel cell

Flow field design for the distribution of reactants and products on the electrode surface plays an important role in the overall performance of the fuel cell. It acts as a crucial factor when the laboratory scale fuel cell is scaled up for commercial applications. In the present work, a novel flow field design is proposed and its usefulness for the fuel cell applications are evaluated in a high-temperature polymer electrolyte fuel cell. The proposed geometry retains some of the features of serpentine flow field such as multiple bends, while modifications are made in its in-plane flow path to achieve comparatively uniform reactant and product distribution. A three-dimensional CFD model is developed to analyze the effectiveness of the proposed flow field. An HT-PEFC is fabricated and experimented with the proposed flow field for experimental validation. Furthermore, a low-cost current distribution mapping device is developed to validate the current density distribution on the electrode obtained from the CFD model. It exhibits a mismatch of 4% in the spatial distribution of current density between the modelling and experimental results. The proposed design is capable of achieving higher uniformity in current distribution across the active area (0.998 for modified serpentine and 0.96 serpentine) compared to serpentine flow field. This aids in boosting the current density of the cell by 27% at 0.57V operations.

Experimental study of variable operating parameters effects on overall PEMFC performance and spatial performance distribution

Back pressure, relative humidity and air stoichiometry, these operational parameters have a crucial influence on the performance of PEMFC. Overall performance, stability and homogeneity of spatial performance distribution under variable operating parameters are in this paper researched. Polarization curves and Electrochemical Impedance Spectroscopy (EIS) are utilized to show the overall performance and resistance losses of PEMFC at variable operating parameters, while the segmented cell technique can provide real-time spatial current density distribution to reflect the uniformity and stability of the performance. Higher back pressure is an effective approach to improve the overall performance of the fuel cell whereas the uniformity keeps constant and the local stability decreases. The back pressure should be limited to some extent (0.3 bar in this paper). With the relative humidity increasing to a value (70% in this paper), overall performance and current distribution homogeneity of PEMFC enhance, but the stability sustains. Under higher air stoichiometry the fuel cell shows better overall and local performance, current distribution homogeneity and local stability. It's found that in all cases the performance near the outlet parts are worst due to poor water management and low gas concentration which could not be effectively enhanced by optimization of these operating conditions.

Visualization of the electric current flowing through conducting structures via magnetic-force microscopy

A technique for determining the spatially distributed current densities of micro-and nanosystems, which is based on measuring the magnetic fields of currents with the use of a magnetic-force microscope and subsequent calculations of the spatial current-density distribution from inversion of the Biot–Savart–Laplace equation, is presented. The technique is tested using specially prepared structures of different shapes with a current-conducting path width of about 1 µm, namely a ring and a meander. Two-dimensional current flow is demonstrated to have features associated with the shape of the tested structures. In particular, it is found that components and the current amplitude are changed at points where the structure shape undergoes variations.

Development of an eight-channel NMR system using RF detection coils for measuring spatial distributions of current density and water content in the PEM of a PEFC

The water generation and water transport occurring in a polymer electrolyte fuel cell (PEFC) can be estimated from the current density generated in the PEFC, and the water content in the polymer electrolyte membrane (PEM). In order to measure the spatial distributions and time-dependent changes of current density generated in a PEFC and the water content in a PEM, we have developed an eight-channel nuclear magnetic resonance (NMR) system. To detect a NMR signal from water in a PEM at eight positions, eight small planar RF detection coils of 0.6mm inside diameter were inserted between the PEM and the gas diffusion layer (GDL) in a PEFC. The local current density generated at the position of the RF detection coil in a PEFC can be calculated from the frequency shift of the obtained NMR signal due to an additional magnetic field induced by the local current density. In addition, the water content in a PEM at the position of the RF detection coil can be calculated by the amplitude of the obtained NMR signal. The time-dependent changes in the spatial distributions were measured at 4s intervals when the PEFC was operated with supply gas under conditions of fuel gas utilization of 0.67 and relative humidity of the fuel gas of 70%RH. The experimental result showed that the spatial distributions of the local current density and the water content in the PEM within the PEFC both fluctuated with time.

Investigating the role of capacitive coupling between the operating table and the return electrode of an electrosurgery unit in the modification of the current density distribution within the patients’ body

BackgroundElectrosurgery units are widely employed in modern surgery. Advances in technology have enhanced the safety of these devices, nevertheless, accidental burns are still regularly reported. This study focuses on possible causes of sacral burns as complication of the use of electrosurgery. Burns are caused by local densifications of the current, but the actual pathway of current within patient’s body is unknown. Numerical electromagnetic analysis can help in understanding the issue.MethodsTo this aim, an accurate heterogeneous model of human body (including seventy-seven different tissues), electrosurgery electrodes, operating table and mattress was build to resemble a typical surgery condition. The patient lays supine on the mattress with the active electrode placed onto the thorax and the return electrode on his back. Common operating frequencies of electrosurgery units were considered. Finite Difference Time Domain electromagnetic analysis was carried out to compute the spatial distribution of current density within the patient’s body. A differential analysis by changing the electrical properties of the operating table from a conductor to an insulator was also performed.ResultsResults revealed that distributed capacitive coupling between patient body and the conductive operating table offers an alternative path to the electrosurgery current. The patient’s anatomy, the positioning and the different electromagnetic properties of tissues promote a densification of the current at the head and sacral region. In particular, high values of current density were located behind the sacral bone and beneath the skin. This did not occur in the case of non-conductive operating table.ConclusionResults of the simulation highlight the role played from capacitive couplings between the return electrode and the conductive operating table. The concentration of current density may result in an undesired rise in temperature, originating burns in body region far from the electrodes. This outcome is concordant with the type of surgery-related sacral burns reported in literature. Such burns cannot be immediately detected after surgery, but appear later and can be confused with bedsores. In addition, the dosimetric analysis suggests that reducing the capacity coupling between the return electrode and the operating table can decrease or avoid this problem.

Measurement of Time-Dependent Changes and Spatial Distributions of Current Density in PEFC and Water-Content of PEM Using a Planer-Surface Coil as an NMR Signal Detector (Second Report: Effect of Relative Humidity and Utilization Ratio of Fuel Gas on Current Density Distribution)

To increase the electric power density of a polymer electrolyte fuel cell (PEFC), it is necessary to increase current density flowing through the membrane electrode assembly (MEA) in the whole PEFC. And this is controlled by the conditions of fuel gas such as flow rate and humidity. We measured the spatial distribution and time dependent changes of current density in the PEFC and the water content in PEM using Nuclear-Magnetic-Resonance (NMR) sensors in order to determine the effect of humidity and the utilization ratio of fuel gas. Our experimental results showed that the current density was uniformly distributed from the inlet to the outlet of the fuel gas when the flow rate was high and the humidity of the fuel gas was 70 %RH. On the other hand, when the flow rate was low and the humidity of the fuel gas higher (85 %RH), the spatial distribution of current density and water content in the PEM was non-uniform. We determined the relationship between the transfer phenomenon of water in the PEFC and this non-uniformity of water content and current density. In addition, a map illustrating the behavior of water content in the PEM and current density under electric-generating condition of the PEFC was made showing the relationship between relative humidity and utilization ratio of fuel gas supplied to the PEFC.

Measurement of Time-Dependent Changes and Spatial Distributions of Current Density in PEFC and Water-Content of PEM Using a Planer-Surface Coil as an NMR Signal Detector (Effect of Relative Humidity and Ratio of Utilization of Fuel Gas on Water Content in PEM)

Measurement of Time-Dependent Changes and Spatial Distributions of Current Density in PEFC and Water-Content of PEM Using a Planer-Surface Coil as an NMR Signal Detector (Effect of Relative Humidity and Ratio of Utilization of Fuel Gas on Water Content in PEM)

Joule heating in nanowires

We study the effect of Joule heating from electric currents flowing through ferromagnetic nanowires on the temperature of the nanowires and on the temperature of the substrate on which the nanowires are grown. The spatial current density distribution, the associated heat generation, and diffusion of heat is simulated within the nanowire and the substrate. We study several different nanowire and constriction geometries as well as different substrates: (thin) silicon nitride membranes, (thick) silicon wafers, and (thick) diamond wafers. The spatially resolved increase in temperature as a function of time is computed. For effectively three-dimensional substrates (where the substrate thickness greatly exceeds the nanowire length), we identify three different regimes of heat propagation through the substrate: regime (i), where the nanowire temperature increases approximately logarithmically as a function of time. In this regime, the nanowire temperature is well-described analytically by You et al. [APL 89, 222513 (2006)]. We provide an analytical expression for the time t_c that marks the upper applicability limit of the You model. After t_c, the heat flow enters regime (ii), where the nanowire temperature stays constant while a hemispherical heat front carries the heat away from the wire and into the substrate. As the heat front reaches the boundary of the substrate, regime (iii) is entered where the nanowire and substrate temperature start to increase rapidly. For effectively two-dimensional substrates (where the nanowire length greatly exceeds the substrate thickness), there is only one regime in which the temperature increases logarithmically with time for large times, before the heat front reaches the substrate boundary. We provide an analytical expression, valid for all pulse durations, that allows one to accurately compute this temperature increase in the nanowire on thin substrates.

Influence of Different Spatial Distributions of Current Density and Spin-Torque Efficiency in the Dynamics of Point-Contact Devices

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper deals with the influence of nonuniform distributions of both current density and spin-torque efficiency on the magnetization dynamics of point-contact devices. Results of micromagnetic calculations show how the inclusion of different spatial profiles could substantially affect both the magnetization dynamics in both time and frequency domain. </para>

A Systematic Approach to Multiphysics Extensions of Finite-Element-Based Micromagnetic Simulations: Nmag

Extensions of the basic micromagnetic model that include effects such as spin-current interaction, diffusion of thermal energy or anisotropic magnetoresistance are often studied by performing simulations that use case-specific ad-hoc extensions of widely used software packages such as OOMMF or Magpar. We present the novel software framework "Nmag" that handles specifications of micromagnetic systems at a sufficiently abstract level to enable users with little programming experience to automatically translate a description of a large class of dynamical multifield equations plus a description of the system's geometry into a working simulation. Conceptually, this is a step towards a higher-level abstract notation for classical multifield multiphysics simulations, similar to the change from assembly language to a higher level human-and-machine-readable formula notation for mathematical terms (FORTRAN) half a century ago. We demonstrate the capability of this approach through two examples, showing 1) a reduced dimensionality model coupling two copies of the micromagnetic sector and 2) the computation of a spatial current density distribution for anisotropic magnetoresistance (AMR). For cross-wise validation purposes, we also show how Nmag compares to the OOMMF and Magpar packages on a selected micromagnetic toy system. We, furthermore, briefly discuss the limitations of our framework and related conceptual questions