Tagged Questions

Formerly FEMLAB, COMSOL is a finite element analysis software package for various engineering and physics applications, with special emphasis on coupled phenomena (multiphysics).

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How does rigid body rotation affect resuts in a simulation?

I have been running a finite-element simulation where, for the sake of convergence, I chose to stay in small deformation hypothesis (in comsol, include non-linear geometry box not checked for who that ...
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Understanding Finite-Element Modal Analysis

I am teaching a basic course on computational physics and for the last part of the course I will introduce freshman physics undergraduates to finite-element modelling methods. I am preparing a ...
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Implicit equation solving COMSOL [closed]

I want to solve a implicit equation in a domain in 1-D geometry. The equation looks like this: i=exp(phi1-phi2-U-i*R) phi1,phi2 are time and space dependent variables. R is a constant. I tried ...
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COMSOL: get list of eigenfrequencies [closed]

In COMSOL, is there a way to get it to export a txt file with all the eigenfrequencies found during an eigenfrequency analysis? I suppose that it could be done through the MATLAB interface or through ...
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Different Meshes Different Maximum velocities

I am working on a model in COMSOL and I am usin different meshes from coarse to fine keeping the other parameters constant. And, I got different maximum velocities for all the meshes. What can I do ...
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Representing a 3D system in 2D (Electromagnetic modelling)

Ok so I'm a complete beginner in computational modelling (I use analytical methods of physics typically) but I would like to model an anisotropic, aperiodic (but not random) finite array of metallic ...
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How to build semiconductor 1-D p-n diode model in COMSOL?

I don't have access to the semiconductors' module, thus I am building my own P-N model. I assumed there would be 4 intervals, ...
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Solving coupled PDE in COMSOL [closed]

I have the system of equations \begin{align} &A \frac{\partial u_1}{\partial t} = 1 - u_1 B \frac{\partial u_2}{\partial y}\\ &\frac{\partial u_2}{\partial t} = \frac{\partial}{\partial y}\...
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Entering an Electric field dependent equation in material contents in COMSOL?

I am trying to model a CNTFET in COMSOL. I am following the same steps that were used to model a MOSFET (provided in the semiconductor module manual), except for a few additional layers and materials. ...
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How to make a good mesh in a biologically accurate model with very small domains

I have been trying to make a biologically accurate 2D spatial model of tissue layers, where different physiological processes happen. This includes mainly chemical reactions, diffusion and fluxes over ...
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Comsol Solver settings for transient fully coupled FSI

I have been struggling to model a transient fully coupled 2D fluid structure interaction. To start with, I tried to redo a published case. It consists of the following settings: Implicit time-...
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3D Divergence-free Stokes equations

I would like to have a divergence-free formulation of the Navier-Stokes equations for creeping flow (a.k.a. Stokes equation, N.-S. without the inertial terms) in 3D, for purposes of tracking particle ...
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Time stepping in comsol multiphysics

I would like to know which is the algorithm Comsol uses in order to correct the time step it uses. For example, when you try to solve an equation you've written in the PDE coefficient interface, and ...
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Stationary solution converge but time dependent doesn't

I've coupled a COMSOL model for fluid dynamics with a very simple pde that model the transport of humidity in air. When I solve it for the stationary case, the solution converge easily, but when I ...
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Can I use RANS to see the effect of mixed convection?

my question is: can I use a RANS simulation to see the effect of mixed/natural convection? Actually I have also a second question: I would like to do this in Comsol multiphysics, but it seems that it ...
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How to include parameters in plot title in comsol? [closed]

I have a comsol model. I want to draw a few plots for different values of a global parameter called plot_z, e.g. if plot_z can ...
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In Comsol Multiphysics, is there a way to change parameter values when something happens in the solution?

I'm beginning to learn Comsol Multiphysics as part of a modelling course in my masters degree. Currently, we are modelling a circuit with a spark gap, which presents some problems for me. I'm using ...