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"Time derivative only allowed with respect to mesh time." New error message...

Hi everyone, I just upgraded to COMSOL 4.2a. When I try to run a model file which works in Comsol 4.2 I get a new error I can't seem to troubleshoot. "Time derivative only allowed with respect to mesh...

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Gold nanoshell simulation. Why the scattering curve is below zero?

Hi, I modified a model of Mie scattering off gold plasmonic nanopartical to simulate the gold nanoshell structure I found on comsol forum. I just add a sphere inside the original particle and built a...

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Thin Film BAW Composite Resonator simulation in COMOSL 3.5a

I'm currently engaged in the simulation of FBAR device in COMSOL 3.5a, and want to use this model. However, "in the model library", I find that the admittance of electrode is defined as...

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extracting data from comsol to matlab through mphinterp

Hello, I have implemented the mphinterp function but when I want to extract results for different parameters something goes wrong. My typical comsolfiles look something like this: - In the Study...

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tumor ablation model

hello, i am trying to make a model like" tumor ablation" model in comsol Heat Transfer Module but i want to change the current from DC to AC current and i want to plot the electric field distribution,...

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Simulation of a floor heating

Hi all, I want to simulate a floor heating in a 2D modell. Floor heating systems release about 90 % of heat in the form of radiation and about 10 % in the form of convection. So is it possible to take...

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How I can add data for a solution to a new study?

I'm working on the simulation of an iron foundry, I made a transient thermal study, and I exported data solution in time 200seg temperatures. I would like to know how I can add the output exported to a...

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Reading Deformation graph

I am getting a coloured graph for deformation in microgripper. Now I want to get the values of deformation at different point(x,y,z) (instead of graph) please let me know how to get that in comsol.

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Detect error with Matlab and go on calculation

Hi, I am running a parametric sweep of my model with Matlab. Sometimes the model doesn't converge, Comsol stops the parametric sweep and send an error message like "Last time step is not converged" ....

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Comsol, Matlab and xmesh-error

Hey, I trie to run my Comsol simulation via Matlab because I want to loop some parameters. For test-reasons I try to run the tomograph tutorial as it solves quick. I'm using Comsol 3.5 but when...

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Comsol issue on Linux

We had a simulation computing for about 3 weeks and paused it to quickly analyse some results. We created a graph and then Comsol stopped responding. It uses 100% of one of the CPU on our Linux...

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Variables

Hi everyone, I have a simple question for you. If I have a variable 'D' , coeficient difusion, depends to temperature (T) with the expression D(T)=0.29*T. the range of temperature is (900 kelvin to...

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parameters

Hi everyone, I have a simple question for you. If I have a variable 'D' , coeficient difusion, depends to temperature (T) with the expression D(T)=0.29*T. the range of temperature is (900 kelvin to...

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Mie scattering in 4.3

Hello, I have already seen some discussion about mid scattering of a gold nanosphere. But I the discussions I have consulted, no one has yet implemented a mie scattering program in Comsol 4.2 or 4.3...

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optical Waveguide

Hi I am defining 2D waveguide from Er:Ta2o5 waveguide in top and bottom of sio2 substrate, now i want to define electromagnetic wave to this.and then i want to calculate the gain. 1-how can i excite...

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Reacting flow, diluted species

Dear all, I am currently simulating the reaction of a dilute compound which flows through a cylindrical tube under laminar flow conditions. I am trying to use the physics method "Reacting flow, diluted...

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What type of boundary conditions to use for a part of electric chain

Hello, I'm not really good with DC, but I have to solve one problem connected to it very closly. I have a model of a bimetallic Copper-Aluminium conductor. I know, that the value of generated current...

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Electron Cloud Confinement

Hi, I am trying to model the confinement of a cloud of electrons in the center of a spherical axisymetric system. The electrons are confined by an electric potential. I was wondering if anyone had...

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deformed parallel plate capacitor

Hi all, I'm working on a model of a parallel plate capacitor in 3D. I'm using the moving mesh, solid mechanichs and electrostatics physics as instructed in others examples. When a pressure is applied...

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Evaluating average value of variable along the length

I am solving free and porous media physics in the square domain (3D). I want to calculate average flow velocity through one of the four sides of the wall along the length. In 2D, I know that we can use...

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