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Frequency domain study - changing the force on a point load with frequency

Hi, I'm having some trouble finding out how to apply a frequency-dependant force. I have a model where up until now, I've been using a non-varying force of 1N on a point load, then performing the...

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Coupling of Drift Diffusion and Heavy Species Transport Plasma

Hello, I would like to simulate a cold plasma (Tritium ions/Electrons) in a tube in a high magnetic field. On one side of the tube there is a potential (some Volts) and on the side walls of the tube...

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Meshing problem

Hi everyone! I am using Comsol 3.5a and cannot figure it out, how to mesh this attached model ... I tried everthing from free mesh predefined mesh sizes (all of them) to boundary layer mesh but I'm...

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plasma module: rate coefficient

Hi plasma model DC Discharge have 5 example three of them :1- argon- dbd-1d 2-dpd-flow -control 3-plasma- display- panel in these example there is a value in Modeling Instructions (Locate the Kinetics...

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Extracting time-dependent data from 2D axisymmetric plot

Hi all, I created a 2D axisymmetric conjugate heat transfer model in 4.3a, and it's time dependent. It's a sphere being heated by moving fluid around its geometry. The output has the temperature...

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Plane Wave Radiation in Transient Analysis

Hello Dear Friends, I want to simulate a simple model via transient analysis. My model is similar to "porous_absorber.mph" (4.3b). My model is more simple. Fundamental difference between two models is...

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end equation

under Variable I define: h = if(T<483[K],-H3*d3*rho*0.25,0) H3, d3 and rho are constants. how can I end the equation h when T is 483[K]? that's mean if T= 483[K], end h , because if the temperature...

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Adding the Kanda factor for Piezoresistive pressure sensors

Hello, I am working on a pressure sensor simulation. How to define non-linearity of materials? I noticed that checking the box of non linear geometry in the study step gives sort of non linearity on...

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sand ripples simulation

Hi folks, I am trying to simulate the formation and motion of sand ripples ( sand particles driven with wind). I think that this process may be considered as a two phase flow or a flow of a mixture of...

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Why does my S11 parameter change when adding a 2nd inactive port?

When looking at off-normal reflection from a periodic structure, my S11 results change when I add a second, unexcited periodic port (S2x). My first periodic port is sending a TM mode in Hy, with...

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Upper and Lower Constraints or limits on variables

I have a model I am trying to run involving the concentration of hydrogen in zirconium and it keeps dropping below 0 in some spots and above 1 in others... It solves several PDE's one of which is the...

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Skin-depth meshing in a two phase fluid model of a cold crucible melting process

Dear Collegues, I'm actually working on a model of a semi-levitating cold crucible melting process. I want to predict the deformation of a metalic mass due to the interaction of EM, hydrodynamic and...

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modeling a rotating electrical machine

Dear Comsol Users, I am trying to model a simple rotating machine in Comsol 4.0a. I am attaching the model file. Unfortunately, I couldn’t find any documentation or examples how to start up a model...

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Differentiation of electric potential

I have used Laplace equation module to compute electric potential for certain geometry. Now I would like to compute electric field lines, but I am not finding a way to do that. Please help regarding...

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error in Frequency-Transient Simulation

Happy new year! everyone recently i have maked a Frequency-Transient Simulation and got a error infomation:"Failed to find consistent initial values. Last time step is not converged." the detail in...

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Integrate on the cross section to find Moment and Torque

Does Comsol have specialised built in functions to find Moment and Torque by integrating over the cross section of a surface modeled by 3-D elements? Say I model 3-D CAntilever beam in Comsol using 3-D...

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hoe do draw a soild cylinder in terms of slices -comsol4.3 version

Hai, I like to know how do draw a solid cylinder in to no of slices in linear direction.please let me know this ,hereby I attached the image of cylinder which one need exactly. regards, N.Kumar

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Continuation Study

Hi, How I'm gonna do if I want to simulate a study which uses previous result to continue. For example, I completed 1st study and get the result, then I want to continue the 2nd study (settings on...

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Ray trajectory with abrupt refractive index distribution

Hi, I am simulating the trajectory of light ray passing through a homogenous material. For example, the light trajectory passes through a magnifying glass. There is a good 3D example in “Model library”...

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Electroanalysis - impedance

Dear all I have tried to browse through documentation and exemplary models to find out what "Electroanalytical Butler-Volmer" kinetics means in terms of concentration polarization. There is no...

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