Query: eddy current brake

title: Analysis and Examination of Eddy Current Brake for Aircraft Using Composite Disc
abstract: This study discusses using eddy current brake (ECB) as next generation non contact brakes in aircraft. This paper describes composite disc ECBs. In this paper, first, numerical analysis using COMSOL Multiphysics was performed and the distribution of magnetic flux density and current density was measured in the disc. From this analysis, it was confirmed that a use of a composite disc reduces the magnetic gap, increases the magnetic flux density, and increases the generated current density. Based on the results of this analysis, the braking torque was measured using an experimental device. Three experiments were performed under three phase AC excitation. The experiment was conducted to study excitation frequency characteristics, excitation current characteristics, and disc rotation speed characteristics. From these experiments, it was confirmed that the braking torque increased when a composite disc was used. In addition, using a composite disc met 80.3 of the braking torque required for regional jets.

title: Magnetic flux distribution and braking torque of a grooved eddy current brake
abstract: Motorcycles generally require an optimal braking system, eddy current brake (ECB) can be used as an alternative to conventional braking systems. Design unipolar axial ECB with an electromagnet used in this research. ECB performance can be influenced by some factor, one of them is changing the form of the surface of a conductor. On this research will discuss the performances of the ECB when the form of the surface of a conductor be varied. Methods used are finite element method (FEM) to view the braking torque and changing magnetic flux, the design and the size of the ECB based on a conventional hydraulic braking system. A flat plate (uniform) will be a reference for comparison to see the braking characteristics of the ECB if the surface is given a groove. Groove variations include half circle, square, triangular, and sawtooth, which will run at speeds of 150 to 750 rpm. The result on the half circle variation has a different trend from the others, sawtooth has the highest average braking torque, while the triangular is lowest.

title: Design and Optimization of an Axial Flux Permanent Magnet Assisted Eddy Current Brake
abstract: In this paper, design method of an axial gap permanent magnet (PM) assisted eddy current brake is proposed by magnetic circuit based modeling and particle swarm optimization. The magnets in the investigated brake topology are placed into slot openings of the structure so as to increase the braking torque. This differs the design from conventional magnet free brake structures. The proposed brake is modeled by a reluctance based network and Newton Raphson approach is used as nonlinear solver. A multiobjective particle swarm optimization is created and used in the design case, which aims to have 28 Nm of braking torque. The optimized model is obtained by nondominating results in three dimensional Pareto surfaces and analytical results are compared with finite element analyses. The results obtained from the analytical approach and the FEA agree well and it is shown that the investigated design methodology is an effective and fast approach so as to obtain the optimized design parameters in such eddy current brake structures.

title: Characteristic Analysis of a Permanent Magnet Eddy Current Brake Under Strong Impact Load
abstract: This paper addresses the braking characteristics of a permanent magnet eddy current brake under strong impact load. The acceleration of the eddy current brake (ECB) will be very large under the action of strong impact load. It is observed that the braking force characteristics of the ECB in high acceleration are different from those under quasi static condition. That is, braking force is no longer a single function of velocity. At first, the quasi static analytical model is established by solving boundary value problems using Fourier series. And then the accuracy of the quasi static analytical model and the two dimensional finite element model (FEM) is verified by comparing the results of the two models. Finally, the braking force characteristics of eddy current brake under strong impact load and the influence of related factors on its braking force characteristics are analyzed using the FEM to provide valuable information for the design of this kind of ECB.

title: Designing an Eddy Current Brake for Engine Testing
abstract: An Eddy Current Brake (ECB) has several advantages making it suitable for using in a dynamometer for testing engines. In this paper, a model is presented which considers the electromagnet's core saturation to predict the performance of an ECB. A design is then proposed for a dual coil, single rotor ECB that meets the design requirement to dissipate a power of 30 kW at 3000 rpm. A comparison between the results obtained for a few different materials considered to be used in the rotating disc are also presented.  Antimagnetic force, Dynamometer, Eddy current brake, MATLAB Model

title: 2D Reluctance Model of an Eddy Current Brake with a Magneto Isotropic Material Structure
abstract: This work shows the model of an eddy current brake with an magneto isotropic material structure. For the modelling of the magneto isotropic material structure made of steel posts, a reluctance network is recommended, since a full FEM model would require too much computation time for optimization purposes. However, in order to map details like the skin effect in the pins, in the reluctance model some details are modelled with the help of fem and thus the required reluctances are determined. The torque calculations of the model is possible with a deviation of less than 10 compared to an experiment.

title: A Novel Approach on the Unipolar Axial Type Eddy Current Brake Model Considering the Skin Effect
abstract: The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignores the skin effect that occurrs during operation. However this phenomenon can not be simply neglected. Therefore, this paper presents a mathematical model of braking torque for a unipolar axial type of ECB system with a non magnetic disk, which considers the skin effects. The use of mathematical models that consider the existence of skin effects is significant in approaching the braking torque according to the actual condition. The utilization of generic calculations to the model of the ECB braking torque leads to invalid results. Hence, in this paper, the correction factor was added to improve the braking torque calculation as a comparator to the proposed equation. However, the modification and addition of the correction factor were only valid to estimate the low speed regimes of torque, but very distant for the high speed condition. From the comparison of calculated values using analytical and 3D modelling, the amount of braking torque at a low speed was found to have an average error for the equation using a correction factor of 1.78 Nm, while after repairing, a value of 1.16 Nm was obtained. For the overall speed, an average error of 14.63 Nm was achieved, while the proposed equation had a small difference of 1.79 Nm. The torque difference from the calculation results of the proposed model with the measurement value in the experiment was 4.9% Therefore, it can be concluded that the proposed equation provided a better braking torque value approach for both low and high speeds.

title: A Timesaving Transient Magneto Thermal Coupling Model for the Eddy Current Brake
abstract: Eddy current brakes (ECB) are widely installed on heavy duty vehicles to improve driving safety and economy. When the ECB works, the mechanical energy of the vehicle is converted into thermal energy under the action of the electromagnetic field, which is a process of mutual influence between the electromagnetic field and temperature field, and this process can be simulated by establishing a transient Magneto thermal coupling model with bidirectional data transmission. However, due to the long calculation time required for accurate 3D electromagnetic analysis, the above model must be simplified. The parameter sensitivity analysis of the ECB shows that the temperature of the eddy current generating location directly affects the braking torque. Through the 3D electromagnetic field numerical analysis, the mapping relationship between the temperature of the eddy current generating layer and the braking torque is established and brought into the transient heat transfer model. The finite difference method is used to calculate the heat transfer model. The calculation results can predict and analyze the braking performance of the ECB during its working process.

title: CEIT Spain Final Report Summary ECUC Eddy CUrrent Brake Compatibility

title: A novel hydrogen turbo expander with active magnetic bearings and an eddy current brake