Store data at certain time intervals
How do I set up my model so the data are not stored at every time step, but at certain intervals. That way I don't end up with huge file, and my plot files for exporting are small as well. Thanks in...
View ArticleWhy is the gradient of the voltage potential field not equal to the electric...
Hi, I have been working on a 3D model of a resistive current sensor, and I am trying to verify the high frequency (50-500Mhz) response. Essentially, i want to make sure that at a fixed current...
View Articlemanaging plots
Is there a way to stop refreshing a plot? I mean, if you realize that you're plotting something wrong, can you give some command to stop the plot immediately? -- Mr. Ezio Cosatto Ansaldo Energia S.p.A....
View ArticleMesh Swept Problem
Dear All, I need to reduce the elements of the mesh in the fluid domain. At the beginning I used a tetrahedral mesh but it is too dense in the axial direction, while I need it mainly in radial...
View ArticleHow I can shrink or expand my simulation box?
Hi all, I have a simulation box to simulate a special form of the diffusion problem (I have my own PDE). I have only one field say density "ro" which varies during the simulation in the box. I want to...
View ArticleCOMSOL Multiphysics 4.3b is now available
Hello COMSOL Community! Five new modules and a tremendous number of new features and enhancements are ready to be applied in your models and simulations. Release Highlights are available at...
View ArticleFuel cell modelling - Electrolyte selectivity issue
I started to model a micro Direct Methanol Fuel Cell (DMFC) with the reference of existing PEMFC model given in the model library. I am using Comsol 4.2a. Since I designed my model as like as the given...
View ArticleError: 2035 Edges are too close in 2D domain
I am simulating electric field distribution between two electrode that are spaced 250microns away. One of the electrodes have a thin dielectric layer (200nm) with a hole of 1micron diameter. I am...
View ArticlePoint Evaluation using Biot-Savart Law.
Hello everyone, I am currently attempting to do a point evaluation with the expression for Biot-Savart Law. The set up is like this: I have an array of points that I would like to get the value at...
View ArticleDe-icing of a wing
Hi, I'm new to COMSOL so please excuse me if my questions seem weird. I'm trying to simulate deicing method used on airplane wings. Right now I'm going for the most simple approach and geometry. So...
View ArticleTotal magnetic Energy
Hello, im Using COMSOL 4.1 and I have got heavy problems simulating the cogging of a synchronous machine. The calculated Torque using the stress tensor is correct. But if I use the method of virtual...
View ArticleError: Internal error: cannot convert ElemStruct to int.
Hello, last week I got a new computer (Windows 7 system) and just tried to run my Comsol models and an error occurs. Whenever I try to run the study I get the following error: Error in sweep: The...
View ArticleAC field Simulation
Hi, I have to do a simple Simulation in comsol multiphysics 4.1 and i am just a beginner in this work,i have to build an electrode geometry and apply various frequency and voltage ac signals and see...
View ArticleHow to define variable regard to time dependent steps?
Hello All I'm running a time dependent AC/DC model, The conductivity of material must be changed regards to voltage differences on two coordinate in each step . I wonder How can I define a variable or...
View ArticleHow to set boundaries as continuity ?
I want set the boundary as a continuity but I don't know how? I know that in Comsol by default the boundaries are define as continuity and it follow this equation: n.j=0 but I want change it to n(j1-...
View Articleapplying a periodic biphasic square waveform to a surface electrode
Dear friends, I want to apply an AC voltage/Current to a surface electrode placed on the human skin. I need a periodic waveform with unequal on and off time. How can I apply this stimulation pulse to a...
View ArticleIonization of air.
Hello. I have a model that comprises a container filled with air. From the outside there are two coils number of turns 1e6 supply current is 1e3 A in the container are two electrodes voltage + - + e7 V...
View ArticleInduction heating
Hi to all! I'm getting some trouble about induction heating using frequency-transient solver. In the 2D-axisymmetric model, I have an aluminium workpiece surrounded by 12 turn of coil (each one setted...
View Articlewhat is "circular dependency " error?
Dear All I,m doing simulation partial discharge by Comsol and Matlab but during simulation I faced this problem, I would be thankful if any one help me for solve this problem. I set two probs under...
View ArticleElectrostatics: relative permittivity
Hi, I am solving an electrostatics model which includes conducting and insulating material. What is the relative permittivity value of conducting material used? All the in built materials use the value...
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