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PML Coordinate Stretching

When I see the equation mode, PML in one of the direction (mapped coordinate e.g. y direction) is stretched to complex number but another remains only real for my 2D analysis, why is that? Also does...

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Mass in not conserved even in conservative form, multiphase flow of water...

Hello everybody, I have previously posted on a problem I was trying to simulate about multiphase flows (Multiphase Flow LS - Air Bubble in Water Cylinder - Conservative forms fails) and I have tried...

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Objective Function Gradient Components in Optimization Module

Hi, I'm using the Optimization Module with V4.2a to run a parameter estimation on a time dependent model. The error output for the Levenberg-Marquardt algorithm doesn't reflect the convergence of the...

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Possibility to import a 2D CAD file to COMSOL?

Hello, I am running the last version of COMSOL (4.3b). I tried to import a 2D CAD file to COMSOL but was not successful! Generally, is it possible to import a 2D CAD file to COMSOL or only 3D files? If...

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Heat source: Temperature profile instead of heat

Hi, I want to use measured values to define a heat source in the "Conjugate Heat Transfer". I could already generate a 3D-function of these values which can be used as Q. But my problem is that the...

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Heat Generation in a Disc Brake

This is a basic related to the "Heat Generation in a Disc Brake" tutorial model. my question is how to add a layer of grease between the disk and the pad. same for the "Heat Conduction in a Cylinder"...

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Regarding beam module in structural mechanics module.

Hi all, Do anyone of you how to add beam module to structural mechanics module.Please help Thanks

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Introduce material with the loss or gain in Transient model comsol 4.2

Hi, I am working at transient model for optical application(wavelength = 1.55um) with loss or gain material and also nonlinear material. I know that I can put loss/gain into my material by introducing...

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Moving Mesh ALE - Applied to unconfined groundwater flow with unknown water...

Hi, I am trying to set up a model that was presented in the paper presented at the 2012 Conference in Milan: Simulation of Pumping Induced Groundwater Flow in Unconfined Aquifer Using Arbitrary...

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principal stresses

Hi all, I would like to extract the principal stresses and plot them using Matlab. I was wondering if someone had already done it and if yes how? Is is better to extract the principal directions as a...

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Geometry variation within Time-Dependent solving.

Hello, I was wondering if it's possible to change geometry according to time ( via internal or external function(MatLab)) ? ie: Making a block depth function of time.

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Interpolation Function Help

Good Morning, I'm having trouble using COMSOL's interpolation function, and I was hoping someone might be able to help. I'm trying to load data from a tab-delimited text file. I've followed the...

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import a bmp image into COMSOL geometry

Hey, as stated in this webpage: 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 simulation, it...

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What's the formulation of "mechanical energy flux" in COMSOL?

There are "mechanical energy flux," "complex mechanical energy flux" which I can derive or plot in the result. They are cool but still I want to know the definitions of them, how it calculates, and I...

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rigid particle carried by a channel flow

Hi I have to simulate the displacement and rotation of a rigid prticule in a fluid flow and I am not a professional on comsol. So, is there anyone who could help me? or if you have any examples of this...

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Hysteresis loss Modelling of Inductor coil

Hello I have simulated inductor using AC/DC module and I have calculated the inductance and magnetic field around the inductor but now I want to calculate the hysteresis loss in the inductor. For that...

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unit normal vector

Hello, I am solving a PDE using coefficient mode. I have a scalar filed, variable C, which has arbitrary boundary inside the domain (picture 1) that evolves with time. I want COMSOL to find the unit...

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Outlet for transient cases in two phase flow

I have problems converging a two phase flow with water and air. When the water exits the computational domain, I can see reflection of water. Also some cases diverge before the water reaches the outlet...

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Scattering boundary condition and port with plane wave

Dear all, I want to simulate the periodic nanostuctures on silicon. now i am using comsol 4.3a version which is not supported PML with port boundary. for that i need to define the Scattering boundary...

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Help understanding how boundary conditions for identity pairs work

Hello everyone, I’ve been reading through these discussions and the Comsol help guide, but am still having trouble wrapping my head around exactly how the boundary conditions for identity pairs work –...

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