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3d laminar flow - solver problem: Segregated group 1.

Hi I´m simulating the convection heat transfer in a pipe. The external surface of the pipe receive solar radiation to heat the fluid that is flowing. I start my model with the laminar flow and after I...

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import a bmp image into COMSOL geometry

Hey, as stated in this webpage: http://www.comsol.com/products/formats/ Comsol can both read and write few types of images. However, when I tried to import a bmp image as my structure for flow...

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Input/Output Error Eigenvalue Solver

While trying to complete a parametric sweep eigenvalue study, the eigenvalue solver produced an Input/Output Error. Does anyone have suggestions on how to go about troubleshooting this error? -Model...

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Convergence issues with level-set conservative form

Hello Everyone, I am trying level-set conservative form for droplet generation in flow focusing device. I have tried the following: (a) non-conservative form: it converges well but mass conservation is...

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Convergence problem of contact mechanics

Hello, Following the earlier discussions on implementing an algebraic equation into a structural mechanics model, I fortunately got away with writing out explicitly an analytical solution. Thanks a lot...

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Direct influcence over automatic time-stepping?

Hi everyone, I'm wondering if it is possible to have a model influence the time-stepping algorithm directly? I know that certain things will cause time-stepping issues and I would like to 'inform' the...

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Geometry optimization

Hello everyone, I´m modeling a simple heat transfer - structural problem, wher I have a 2-D rectangle with a hole in the midle. First I apply a Temperature load that produces expansion in the...

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Cluster computing got stuck :external progress scheduling

Hi,Ihave recently setup a cluster and i had comsol 4.3 on the head node,and i had the installation forder shared, model working directory shared. However,when I am trying to submit a batch job,using...

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when to use parameters, variables, and functions

Hi All, Considering global values for now. It seems clear to me when to use parameters - any value that is independent of the independent or dependent variables. But when is it appropriate to use...

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Thermoelectric Effect - Adding the physics

Hello, I'm working in a project on thermoelectric generator. As 'Thermoelectric' physics interface,is not in the physics area/physics list, I was trying to add the physics using the steps given in the...

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parametric sweep

How to add parameters for the circle centre coordinates, and update parametric sweep settings , for change the distance between the two coils -- kishore Naik Mude

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com.comsol.nativejni.FlNativeException: Incorrect size of returned vector

Dear all, I'm working on a 2D PDE in coefficient form. In my model, one of the coefficients is set up by an external matlab function fun(t,x,y) according to:...

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Temperature and time-controlled heat generation

hello, I have a model in which (thermally induced) to start a reaction that takes place when reaching a specified temperature heat generation to another. has the heat generation is always a period of 2...

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Which new feature(s) du you prefer in 4.3a ?

Hello I wanted to say to everyone: take a look at the Help: Mathematical "functions" and to "operators" there we have now got many newcomers given new flexibility to the GUI analysis, both for...

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Assing a sinusoidal body force F(x,y,z,t) in comsol 4.3

Dear all, I am trying to simulate shear wave propagation in tissue using a PDE wave equation (I manually defined the equations). In my geometry, I have a 3D box (imaging it is tissue) and in the center...

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Conductivity of the antenna, RF module

Dear All, I have question concerning optical antennas. I have model which consist of the optical antenna on substrate, and I want to calculate scattering cross section and field enhancement. My...

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Domain Point Probe Inconsistency

Hi All, Like many newcomers to COMSOL, I'm having trouble with the Results section. As per suggestions on some other posts I've found, I have been using domain point probes to visualize a variable...

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Oscillations

Hi All, I had a quick question, I'm seeing oscillations emerge in my model (a 1D mass flow situation), and I was wondering: is it possible for these oscillations to emerge due to the solver (too coarse...

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Acoustic Band Structure in 2d

Hi Folks - Ive posted a couple of questions to some related discussion but it looks like they haven't been visited in a while so I thought I would make a new discussion group. I am interested in...

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Identity pair as port source in Comsol 4

Hi all Does anybody knows how to set "identiy pair" as "port" in Comsol 4.0a or 4.1? I am calculating the reflectance and transmittance in Comsol. Previously, I used Comsol 3.5a for this work (refer...

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