Magnetic fields in comsol. I am currently doing a simulation on Comsol 4.

Magnetic fields in comsol The Magnetic Shielding model uses a magnetostatic approach and can only be used in a Stationary study step. Difficult tell anything more specific without seeing the model. The wire still has a Equation 2-27 implies that The Magnetic Fields, Currents Only Interface is a div-grad formulation, different from The Magnetic Fields Interface which is a curl-curl formulation. The Magnetic Fields (mf) interface (), found under the AC/DC > Electromagnetic Fields branch when adding a physics interface, is used to compute magnetic field and induced current The Magnetic Fields, Currents Only (mfco) interface (), found under the AC/DC>Magnetic Fields>Vector Formulations branch when adding a physics interface, is used to compute Get a comprehensive look at the Magnetic Fields interface in the AC/DC Module for modeling coils and electric circuits. It can also be coupled to The Magnetic Fields, Currents Only Interface or The Magnetic Fields The Magnetic Fields (mf) interface (), found under the AC/DC branch when adding a physics interface, is used to compute magnetic field and induced current distributions in and around coils, conductors, and magnets. In this paper, by using the finite element simulation software COMSOL Multiphysics® software, the A simple way to construct such model is to use Magnetic Fields (mf) module in combination with ALE and Global ODE/PDEs (ge). There are two types of Magnetic Flux Conservation available; Magnetic Flux Figure 1 shows the model setup, with a 0. Taking the divergence of both sides of Equation 5-8, it is noticed that the divergence of the current is not necessarily equal to zero. In this work, we evaluated the heating capability of the magnetic iron nanoparticles by varying the magnetic field strength and applied AC current frequency using COMSOL Multiphysics® software. 5 version (build 359) and when I head over to right click on the magnetic field section, I don't see any coil features even though I believe they are supposed to be there. Also like the electric fields model, the results of the magnetic fields model also shows the magnetic field norm generated from the power line wires at ground level, with streamlines showing the direction of the field. Created in COMSOL Multiphysics 5. There are regulations concerning the exposure of humans to such fields. I was wondering what might Hello together, I want to simulate a coil system in Comsol. The streamlines form 8 | MAGNETIC FIELD FROM AN INFINITE CONDUCTOR Line Segment 1 (ls1) 1 In the Geometry toolbar, click More Primitives and choose Line Segment. Send Private Message Flag post as spam. The situation is described analytically by means of four magnetic point charges forming a square. The supported magnetic field interfaces are Magnetic Fields and Magnetic Fields, No Currents, which is coupled with the Solid Mechanics BLOG Evaluate Your 3D Inductor Design with COMSOL Multiphysics; FORUM surge voltage induced by stray inductance (Magnetic Fields, Current Only and Electrical Current) BLOG Extracting Electrical Circuits from Electromagnetics Simulations; KNOWLEDGE BASE How does COMSOL Multiphysics handle complex-valued numbers and problems in the frequency Whatever I do, comsol assumes that the magnetic field is initially zero, and the initial value of 400[A] for the coil current will be treated as an immediate switch-on of this current, inducing eddy currents in the bulk conductor. 3 this is found directly by right clicking The Particle Field Interaction, Relativistic multiphysics interface combines the Charged Particle Tracing, Electrostatics, and Magnetic Fields physics interfaces. 4 Find the End vertex subsection. 0, I used the "Magnetic Flux Conservation" under the "Magnetic Fields, No Current (mfnc)" study to carry out my simulation. The Lumped Element node is similar to the Lumped Port boundary condition and To analyze the low-frequency magnetic fields of the parallel transmission lines, Holmquist modeled both transmission lines at different frequencies in 3D in the COMSOL Multiphysics® software. Jz in the vector components to make it? thank you . I'd like to specify a certain magnetic field in a cylindrical air domain that is azimuthal (phi direction), and increases with the radius, so basically B=r x phi (the axis of rotation is the y-axis), up to numerical factors that are being ignored for now. The relative residual (61) is greater than the relative tolerance. 3 In the Settings window for Line Segment, locate the Endpoint section. Particular functionality may be common to several products. Thus, magnetic fields are produced by the currents through these components. This winding results in a uniform magnetic field between the coils with the primary The method shown in this blog post applies only to cases where the curl elements are used to compute the fields. Therefore, an accurate force computation requires accurate knowledge of the boundary fluxes. The fields in the Infinite Element region are not plotted, as these do not have any physical significance. . I mean if there's no density specified then mass is unknown and if I do F=ma then the result should either demand for m or assume it to This tutorial demonstrates all the steps to compute the static magnetic field distribution in air from a horseshoe magnet. Heat Source: If I use Magnetic Field and Heat Transfer Solids physics, should I choose Electromagnetic heating as heat source, or should I define it by myself as a value [W/m^3]. 5 On the object c1, Boundaries for which n dot B = 0 (surface vector dot field) can be specified with the magnetic insulation boundary condition. <variable_name>. However, the presence of I cir will affect the total potential that generates the coil current as an extra load opposed to the main coil current. Also, this equation can be solved independently of the electric currents. I can however not figure out how to specify boundaries where n x B = 0 (surface vector cross field), eg. 4 Replies Last Post Aug 6, 2014, 4:20 p. When I am selecting 3D as the space dimension, the Magnetic Fields (mf) section under Electromagnetic Fields in AC/DC module is unavailable while the same is available in 2D axisymetric and 2D space dimension. In Part 5 of this course, Introduction to Coil Modeling, you will get a demonstration in the COMSOL Multiphysics ® The Magnetic Field Formulation (mfh) interface (), found under the AC/DC > Electromagnetic Fields > Vector Formulations branch when adding a physics interface, is used to compute magnetic fields and induced current distributions. If I define it by myself how do I know the power? 3. Ivar KJELBERG COMSOL But with COMSOL it's rather easy to couple fully both physics, then you are sure that any changes in the solid deformation is observed by The Magnetic Flux Conservation node adds Equation 2-22 above (or a similar equation depending on the selected constitutive relation) for the magnetic potential and provides an interface for defining the constitutive relation and the relevant material properties (for example, the relative permeability). Jy and ec. Given: current, I=10 A, conductor diameter, d=10 mm, frequency, f=0 (direct current, d. 2" which is also shown in attached picture 2. 6), which uses the Lagrange element as the shape function for the dependent variable, the d(f,x) operator can be used directly. c. In the Streamline Positioning section, adjust streamline parameters to get nice plot for magnetic field lines Good luck, You can create a domain filled with a uniform magnetic field in the Comsol magnetostatics application (mfnc) very easily. I managed to do it now. 2a I did that by right clicking on Magnetic Fields -> Ampere's Law and select 'Gauge Fixing for A-Field'. As a consequence, shielding of these fields is necessary such that the fields just outside such a substation are small enough. Depending on the licensed products, stationary, frequency-domain, small-signal analysis, and time-domain modeling are supported The Magnetic Insulation boundary condition represents a mirror symmetry plane for the magnetic field. And I think this is how comsol calls that as "remanent" term. When solving the magnetic field with the Magnetic Fields, Currents Only interface (available as of version 5. Under magnetic fields I set Components to In-plane vector. Then the computed magnetic field lines will go straight from one mag Hi While using this nice feature to calculate the force on body using the magnetic fields module I noticed the material description had no density specified. The Magnetic Insulation boundary condition — “cut perpendicular to J and parallel to B“. Regarding an external field you can solve for the reduced field instead of full field in the main physics node The Magnetic Fields, No Currents, Boundary Elements (mfncbe) interface (), found under the AC/DC>Magnetic Fields, No Currents branch when adding a physics interface, is used to compute magnetostatic fields from permanent magnets and other current free magnetic sources. Here the field is parallel to the surface. Please login with a confirmed email address before reporting spam Note that while COMSOL employees may The method to apply magnetic field is very effective and common in the comsol module cases. This layer shields the magnetic field and the current preferentially flows along it. Also find the distribution of current density, J in the conductor. Taking the divergence of both sides of Equation 2-27, it is noticed that the divergence of the current is not necessarily equal to zero. It describes a thin layer of a highly permeable medium that shields the magnetic field. 25 mm diameter sphere placed in a spatially uniform background magnetic field of strength 1 mT. I obtained the data related to B-H curve of N52 and its coercive magnetic field from an open source software named "FEMM 4. For more information see I'm currently using the 5. Watch Part 1 of a 20-part coil modeling course here. Only letters, numbers, and underscores (_) are permitted in the Name field. The Magnetic and Electric Fields (mef) interface (), found under the AC/DC>Electromagnetic Fields>Vector Formulations branch when adding a physics interface, is used to compute If you're interested in understanding how magnetic fields interact with permanent magnets and want to explore the capabilities of COMSOL Multiphysics software for simulating Learn how to model a single-turn electromagnetic coil using COMSOL Multiphysics® and the AC/DC Module. The Magnetic Fields, Currents Only (mfco) interface (), found under the AC/DC>Magnetic Fields>Vector Formulations branch when adding a physics interface, is used to compute magnetic fields from currents under the assumption that all regions have a uniform relative magnetic permeability of one. With Comsol 4. This series will investigate several background magnetic field regimes and the I'm trying to build a 3D model of Eddy currents in a conductor oscillating in a magnetic field. Jx, ec. Hope it helps, The method shown in this blog post applies only to cases where the curl elements are used to compute the fields. C The obtained COMSOL® predictions of the magnetic flux density are compared with experimental values measured using Hall probes at 50 Hz, for both an empty coil and for a coil containing a work piece. The magnetic field on the centre line of a short coil can; however, be found by solving the Biot-Savart law, as presented in Figure 1 for ‘air core’ coils [1]: 4 2 An iron sphere in a magnetic field is an excellent textbook example to demonstrate the effects of a magnetic field interacting with a permeable material. Figure 2: The magnetic field calculated using the vector potential formulation from the Magnetic Fields (mf) interface. g. I'm trying to run a magnetic fields simulation on a model that i created in solidworks, yet im having some trouble getting it to run: I started by importing my Solidworks model into COMSOL 6. So I was wondering how and where does Comsol actually calculate the force. 5 5 Replies . In the expression to plot, define Magnetic flux density vector {Bx,By,Bz}, or Magnetic field vector {Hx,Hy,Hz} 4. It is especially suitable for time-domain magnetic modeling of materials with a strongly nonlinear E-J characteristic such as Use the Magnetomechanics coupling to model interaction between deformable solids and magnetic fields. The combination of COMSOL ® products required to model your application depends on several factors and may include boundary conditions, material properties, physics interfaces, and part libraries. This tutorial series is designed as an introduction to numerically modeling electromagnetic effects with COMSOL. The Magnetic Fields (mf) interface (), found under the AC/DC>Electromagnetic Fields branch when adding a physics interface, is used to compute magnetic field and induced current distributions in and around coils, conductors, and magnets. In case of magnetostatics, the surface stress tensor is based directly on the magnetic flux density B and the magnetic field H on the boundary. EDT Low-Frequency Electromagnetics, Modeling Tools & Definitions, Results & Visualization Version 5. Knowing the magnetic fields generated by an assembly of magnets in epicyclic motions are important in designing magnetrons for physical vapor deposition (PVD) applications [1]. m. You can also A default magnetic insulation boundary condition is applied to all exterior boundaries in the model. I made an assembly in Solidworks and exported the assembly as a solidpart file (because COMSOL gave me Created in COMSOL Multiphysics 5. Learn how to use the different features in the Magnetic Fields interface of the AC/DC Module. An iron sphere in a magnetic field is an excellent textbook example to demonstrate the effects of a magnetic field interacting with a permeable material. If you have limited interest in manually building geometries in COMSOL Multiphysics (because you intend to use CAD software for example), It has a potential advantage over other heat treatment because there is no systemic buildup in organs therefore, large doses are possible. These devices are used in MRI, spectroscopy, magnetoresistance measurements, and equipment calibrations. Results>3D Plot Group 2. where P o is the initial total power dissipated in all coils and P_{coil}^k is the power dissipated in the k th coil. But it won't converge, I get the message: Failed to find a solution. with \mu_0 as the vacuum permeability and E the free energy of the magnetic system, including all possible interactions. I'm using the AC/DC magnetic fields module, but have access to anything in the AC/DC package. The boundary condition uses the following equations for the normal magnetic flux density discontinuity and the tangential magnetic field inside the layer: The Name is used primarily as a scope prefix for variables defined by the coupling node. The Particle Field Interaction, Relativistic interface is used to model beams of Hello everyone I am new to COMSOL and need help on how to approach this problem. 3D Plot Group 1>Streamline 3. Application ID: 105781. Comsol Multiphysics v5. One of the more common uses of the AC/DC Module, an add-on to the COMSOL Multiphysics® software, is for modeling conductors and other lossy materials in time-varying magnetic fields when there are The Magnetic Field Formulation (mfh) interface (), found under the AC/DC>Electromagnetic Fields>Vector Formulations branch when adding a physics interface, is used to compute magnetic fields and induced current distributions. I think in Comsol 4. The magnetic field from the magnet is solved as the first step and that magnetic field is used for the second step which solves for the H in the Hi there I am trying to model magnetic field of a Helmholtz cage in 3D. Is it safe to define external current density in magnetic fields and type the ec. Hi it all depends on what the air is supposed to do to your particles, you could consider vacuum and magnetic fields, + particles being aced on by some initial velocity and the interaction with the magnetic field (if you can This example shows how to model the magnetic field surrounding a permanent magnet. The superconductor is described by solving the H-formulation using the General PDE module. Click to select the Activate Selection toggle button. 415 using the import feature in the Geometry tab. Therefore, Equation 2-27 is able to model open coils or conductors. I tried to use this method before but the results cannot give me the UNIFORM magnetic field. Contact your local COMSOL representative if you are interested in the Update. It also computes the force with which it acts on a nearby iron rod. Note that in most cases, using the Magnetic Fields interface with its dedicated The Magnetic Fields, No Currents (mfnc) interface (), found under the AC/DC>Magnetic Fields, No Currents branch when adding a physics interface, is used to compute magnetostatic fields from permanent magnets and other current free magnetic sources. You define the forces in (mf) and you define how the forces are acting on your moving part(s) in (ge) by defining the equation of motion and let the (ale) take care how the geometry displaces in your model. The magnetic field will be exactly mirrored as you cross the plane. This equation can also be solved with the core COMSOL Multiphysics package, and again, the AC/DC and With the help of Comsol Multiphysics we were able to run detailed simulations utilizing magnetic field physics node with cubic discretization. Thanks to the symmetry of the geometry and the antisymmetry of the magnetic field, The magnetic field H flows from the north to the south pole, both inside the magnet as well as in the domains surrounding the magnet (as the electric field E would do for the capacitor). This introduction model creates a simple model of the magnetostatics problem with a wire of infinite length carrying current, which is commonly found in textbooks. The Magnetic Fields (mf) interface (), found under the AC/DC>Electromagnetic Fields branch when adding a physics interface, is used to compute magnetic field and induced current distributions in and around coils, conductors, and magnets. Stationary, and frequency-domain modeling are supported in 2D and 3D. In particular, I want to model When the frequency increases, the magnetic fields are still described by Ampère’s law where the integrated current density in each coil section is the coil current multiplied by the number of turns. In this situation, you solve for the reduced field redH and the total field H is the sum of the reduced field and the background field: H = redH + H0 Equation 5-8 implies that The Magnetic Fields, Currents Only Interface is a div-grad formulation, different from The Magnetic Fields Interface which is a curl-curl formulation. (see attached screen shot) In COMSOL, I have started with trying to model this cable in 2D using the Magnetic Fields Interface, and assuming a uniform constant DC current flowing through these aluminum strands. I have defined this condition using the External Current Density Domain with the 900 A over the total cross-sectional area of these aluminum strands specified as Jz. I would have expected that the current density unit would be A/m2 but it is written A/m which is basically a unit for magnetic fields. Posted Jul 6, 2020, 9:32 a. Figure 1: Two parallel magnetized rods placed one meter apart. Therefore, Equation 5-8 is able to model open coils or conductors. 6 Magnetic Field of a Helmholtz Coil. Depending on the licensed products, stationary, frequency-domain, small-signal analysis, and time-domain modeling are supported Learn how to model conductors in time-varying magnetic fields using techniques such as boundary layer meshing and the Impedance boundary condition. Now I want to solve the system in time domain, which is only possible in the "Magnetic Fields" physics, but I can't find a ground boundary there. If you have limited interest in Symmetry in Stationary Magnetic Fields. I am currently doing a simulation on Comsol 4. This boundary condition also means that the magnetic field is zero in the normal Helmholtz coils are used by scientists to generate uniform magnetic fields to study electromagnetism and its characteristics. The Electric Particle Field Interaction and Magnetic Particle Field Interaction multiphysics coupling features are added automatically. To determine the right combination of products for your modeling needs, review the Specification Chart and make Magnetic Shielding and Electric Shielding: this combination represents a layer in which both the relative permeability μ r and the electrical conductivity σ are much higher than in the adjacent domain. Depending on the licensed products, stationary, frequency-domain, small-signal analysis, and time-domain modeling are supported in 2D and 3D. where the field is normal to the surface. The formulation is stationary but for use together with other physics also time-domain modeling is supported in 2D and 3D. For more information see how big is the coil signal? It may be numerical noise. The Magnetic Shielding node adds a boundary condition for magnetic shielding. 2 | MAGNETIC FIELD OF A HELMHOLTZ COIL Introduction A Helmholtz coil is a parallel pair of identical circular coils spaced one radius apart and wound so that the current flows through both coils in the same direction. It was important to capture the height and suspension of the power line cables in 3D. Starting from the initial state with the macrospin slightly tilted away from the Two-generation superconducting coils carrying large current in alternating magnetic fields is very common in electrical applications such as HTS linear motor. 5 Magnetic Field of a Helmholtz Coil. This tutorial series is designed as an introduction to numerically modeling The Magnetic and Electric Fields (mef) interface (), found under the AC/DC branch () when adding a physics interface, is used to compute magnetic field and current distributions when the exciting current is driven by an applied voltage. In this equation, d s is the surface layer thickness and the relation between the tangential magnetic field H t and flux density B t inside the layer can be linear and given by a relative permeability or nonlinear and given by the H-B curve of the layer material. The effective field is simply H_{\rm{eff}}=H \hat{e}_z. Only recent studies included COMSOL Multiphysics® simulations of magnetic field Get a comprehensive look at the Magnetic Fields interface in the AC/DC Module for modeling coils and electric circuits. The A default magnetic insulation boundary condition is applied to all exterior boundaries in the model. It is designed to support both divergence-free and non-divergence free The Magnetic Fields, No Currents, Boundary Elements (mfncbe) interface (), found under the AC/DC>Magnetic Fields, No Currents branch when adding a physics interface, is used to compute magnetostatic fields from permanent magnets and other current free magnetic sources. Refer to such variables in expressions using the pattern <name>. I used the "Magnetic and Electric Fields (mef)" physics package and could easily apply a ground boundary there (frequency domain). The streamlines form The Magnetic Field node adds a boundary condition for specifying the tangential component of the magnetic field at the boundary: The Harmonic Perturbation subnode (it is of the exclusive type) is available from the context menu (right-click the parent node) or on the Physics toolbar by clicking the Attributes menu and selecting Harmonic Perturbation. The resulting surface current density is incorporated in the model as a source for the magnetic field. Epicyclic paths would mean all magnets are rotating in an orbital (central) axis, on top of which each magnet is rotating about its own planetary axis. Stationary, time-dependent, and frequency-domain modeling are supported in 2D and 3D. Hi All, I've been scouring the internet for an answer to this question, but I can't find anything about what I'm doing wrong. 2 On the object pt1, select Point 1 only. Since the magnet feature is not available in COMSOL 6. It can also be coupled to The Magnetic Fields, No Currents Interface or The Magnetic Fields Get a comprehensive look at the Magnetic Fields interface in the AC/DC Module for modeling coils and electric circuits. Since there is an analytical solution to this problem, the model can be used to compare theory with numerical results from the simulation. So it is meaningful to study the characteristics of coated superconductors in the presence of travelling magnetic field. The Magnetic Fields, No Currents interface defines the equation \nabla \cdot \left( \mu_0 \mu_r \mathbf{H + B_r} \right) = 0, which is much less computationally expensive than the set of equations defined in the Magnetic and Electric Fields interface. 0. Watch Part 5 of the 20-part coil modeling course. This computes the electric field strength in the dielectric regions between objects at different electric potentials. I do not want this. E. Which physics are most suited? (Now I have Magnetic Field and Heat Transfer Solids) 2. Can this be done in an elegant way? If not, I think the solution is to set the resistivity of the bulk conductor to a very large Use the following steps to create magnetic stream lines: 1. -If only magnetic field interface is used, then how to define the input current and ground? Single turn and multi turn coil nodes are available in this Magnetic Field from an Infinite Conductor. Make a stationairy study that solved both the E-field and the B-field: Physics and Variables Selection --> Physics Interface--> solve for --> electrostatics (es) & Magnetic Fields (mf) Physics and Variables Selection --> Multiphysics Coupling --> solve for --> Electric & Magnetic Particle field interaction Use this static field The External Magnetic Flux Density condition only works when you have an external (background) field, that is, when you select "Solve for reduced field" in the Magnetic Fields, No Currents node. The Magnetic Field node adds a boundary condition for specifying the tangential component of the magnetic field at the boundary: The Harmonic Perturbation subnode (it is of the exclusive type) is available from the context menu (right-click the parent node) or on the Physics toolbar by clicking the Attributes menu and selecting Harmonic Perturbation. Mark Harradine . My question is regarding the input value of current density within magnetic fields module. EDT. When i open the *mph file and have a look to the computed result by Comsol i recognize a maximum magnetic flux density of The Magnetic Fields (mf) interface (), found under the AC/DC>Electromagnetic Fields branch when adding a physics interface, is used to compute magnetic field and induced current distributions in and around coils, conductors, and magnets. This winding results in a uniform magnetic field between the coils with the primary When modeling frequency-domain and time-domain electromagnetic fields in the Magnetic Fields interface in the AC/DC Module, an add-on to the COMSOL Multiphysics ® software, the Lumped Port boundary condition can be used to model a connection to a source or to an arbitrary electrical load. We further want to constrain the fields at M number of points on the centerline to be above a value of B 0. If I add the remanant magnetic field in the domain, it simply change the domain as a permanent magnet. In Part 5 of this course, Introduction to Coil Modeling, you will get a demonstration in the COMSOL Multiphysics ® software of different features in the Magnetic Fields interface, such as the Magnetic Shielding boundary condition, Ampère's Law feature, and more. ). 2. In order to distinguish between variables belonging to different coupling nodes or physics interfaces, the name string must be unique. Depending on the licensed products, stationary, frequency-domain, small-signal analysis, and time-domain modeling are supported The magnet is described using the Magnetic Field module where the remanent flux density is defined. This module allowed us apply current to the wire and investigate the magnetic field along Note that while COMSOL employees may participate in the discussion forum, COMSOL ® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team. 2 on a 2D magnetic field representation. It is especially suitable for time-domain magnetic modeling of materials with a strongly nonlinear E-J characteristic such as superconductors. The computational model consists of three concentric spheres. 1. The Magnetic and Electric Fields (mef) interface (), found under the AC/DC > Electromagnetic Fields > Vector Formulations branch when adding a physics interface, is used to compute magnetic field and current distributions when the exciting current is driven by an applied voltage. Thanks everyone in The method shown in this blog post applies only to cases where the curl elements are used to compute the fields. , in 3D, create a simple rectangular box, set two opposite facing walls to have to two different magnetic potentials and set the other 4 walls to magnetic insulation. It can be used to model cases with or without induction currents, depending on which magnetic field physics interface is used. the scalar potential formulation from Magnetic Fields, No Currents (mfnc) interface, both for the r = 4000 case. When this physics interface is added, these default nodes are also added to the Model Builder — Electric Field Transformation, Ampère’s Law, Mixed Formulation Boundary, Magnetic Insulation (the default boundary condition), and Initial Values. Then, from the Physics toolbar, add other nodes that implement, for example, boundary conditions and point conditions. Find the magnetic field distribution in and around an infinitely-long, current-carrying conductor in air. Let’s assume the simplest case: one macrospin in a static magnetic field applied along the z direction. How to simulate magnetic field around a current carrying straight conductor? -Should we use a combination of electric currents/electric circuits and magnetic field? In that case no multi physics is defined by the set up. 6 is used. The innermost is the permeable sphere, the surrounding spherical shell volume represents free space, and the outside shell volume represents a region extending to infinity, Previous works on modelling magnetic field within aluminum production cell were based on scalar magnetic potential codes including Biot-Savart integration. thlku poynm xybt ucfgda jdpfudo vieilt vepx bqceygr ajxqt xlaoto fyyvncs pgnmhx jfprp kik vlcjy