mf and mef huge difference
Hi, I want to compare mf and mef physics in order to know which one I have to use for my study. I work with a coil and a conductive core. I'm interesting in the electromagnetic power dissipated in...
View ArticleWhat is the exact electric field expression when using the PORTs? -...
Dear all, In the attached 2D model, I use 'Electromagnetic Waves frequency domain' and I would like to study the light propagation inside my structure. I would like to have a input power flow at port 1...
View ArticleVariable exchange between Matlab and Comsol
Hello everyone, I am running Comsol using the LiveLink with Matlab and am trying to do the following: I have a value, dt, which is 0 everywhere in the beginning. (I can either use dt=0, make an...
View ArticleError in compile Equation: Frequency Domain
Hello everybody, I am simulating a microwave devise in optical frequencies but I see this error: Feature: Compile Equations: Frequency Domain (sol1/st1) Error: error in multiphysics compilation I would...
View ArticleHow to use interpolation function in parameters?
Dear users, I have defined a piecewise function from a file with function name 'functionName' in Global Variables. I would like to define a parameter that uses this function in Global Definitions ->...
View ArticleVariable change with time
I have a question about variable change with time. I try to make a mass transfer model. The inflow concentration change with time. If t <= 1000s then C=1mol/m^3 else C=0 I upload the data and make a...
View ArticleStructural Mechanics Equation System
I am trying to understand how my structural mechanics model is computing its solution. The model solves and gives me a reasonable solution. However, I don't understand how it is arriving at its answer....
View ArticleElectromagnetic Induction Tomography simple model
Hi, I am trying to make a very simple 2D model where I have 2 coils in which in between is a medium (air). One of these coils will be excited and have a magnetic field in the direction of the second...
View Articlefor NdFeB magnet, which constitutive relation is closer to reality
I'm modeling two NdFeB magnets placed very close to each other in a repulsive manner. I need to compute the repelling force between them. There are two options for the constitutive relation. One is B =...
View ArticleConvergence issue with nano pore electrodeposition model
I am trying to model electrodeposition into a nanopores but am having troubles with convergence. My solution only converges to 1e3 fairly consistently even if I refine the mesh and then it starts to...
View ArticleCFD - Surface roughness
Hey guys I really need your help on this one! I was wondering if any of you could tell me about the default settings of surface roughness's in COMSOL? All I've found about it in the documentation is...
View ArticleWhen I have to use 2d or 3d modeling?
Hi Everybody! I´m Wagner, from Brazil and I have a question, a simple question I think! How I decide if my modeling will be in 2d or in 3d? I have Heat Transfer and AC/DC model and I work calculating...
View ArticleHeat Transfer in Fins- Help needed
I am trying to simulate a heat sink, very similar to the one shown in the tutorials... In spite of building a coarse mesh, the solution does'nt converge even after 2 hours of solving. I have an i5...
View ArticleHow can I define nonlinear electric conductivity ?
Hi, I'm currently working on electrical simulation using AC/DC module. How can I define nonlinear electric conductivity of zinc oxide (ZnO) in subdomain settings?
View ArticleProblems with multicore time calculation
Hello everyone, I am working with the attached file and there is a very unusual behavior with the second study. It is a frequency response study with a parametric sweep: I need to know the frequency...
View ArticleCombination of Fluid Flow and Heat Transfer
Hello everyone, I am a new member of this forum and also a fresh user of COMSOL. I hope I will be able to learn from and discuss problems with all of you. My first enquiry to the forum follows: My...
View ArticleHow to use user defined functions as physics's input? Thanks!
Hello, every one! I am learnging to use COMSOL4.2 and want to add AC signal as my device's input. Just as Eric told me to write an equation as the input....
View ArticleImporting a file from AutoCAD to COMSOL
I have created a 3D building model on AutoCAD and wish to import it to COMSOL for CFD analysis. Can I know the process for importing?
View Articleconvective heat flux magnitude
Hi , I'm computing heat transfer from a rotating hot sphere in a fluid medium. The flow is creeping type. I have issues related to the various COMSOL options for convective, conductive and total heat...
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