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Undefined value found.

I am using poroelasticity module to simulate soil behavior of porous materials, the error information is as follows: Undefined value found. - Detail: Undefined value found in the stiffness matrix....

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COMSOL Error Message

Hi I've been problems with COMSOL in Plasma Module The following feature has encountered a problem:"The source selection for the operator intpot1 must be nonempty. Error in multiphysics compilation. -...

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Setting temperature initial condition at specific location

Hello, I'm trying to solve a porous media heat transfer problem. the geometry of the problem includes 10/200 meters rectangle, where I'm setting a linear temperature gradient by the following equation:...

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Why COMSOL still requires the Young's modulus and Poisson ratio when defining...

Hi all, I want to play with Comsol for 3D simulations of linear elastic material. The materials are anisotropic so that I define elasticity matrices for them. But Comsol still requires me to give...

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How to use Laminar Flow Pressure results in Solid Mechanics, help?

Hi, I need to use as an input in the Solid Mecanic module the Pressure results from Laminar Flow calculations. Can anyone explain me how to do this? thank you for yor answer. Best regards, Leonardo.

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Postprocessing in cyclindrical coordinates

I am doing a plane strain analysis of a pipe with a crack in it. I would like to get the stress components in the cyclindridcal coordinate system (radial, hoop stress) rather than in the cartesian...

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Particle Data Extraction

Hi there, I made a simulation of an electro-kinetic flow within a 2-phase medium, and after computing the currents I wanted to see how particles would behave within the geometry and the resulting...

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How to solve the problem"Attempt to evaluate non-integral power of negative...

Hello, I am solving a Drift diffusion model for plasma using general form PDE. However, I am facing the following error, Failed to find consistent initial values. Attempt to evaluate non-integral power...

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Pressure in Reacting Flow in Porous Media

Hello All, I am running a model in 4.3a with the node "Reacting Flow in Porous Media," and simulating groundwater flow in a confined aquifer. When I look at the results, my average pressure gets down...

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Cloth or flag modeling

Hi all, Does anybody have a COMSOL model that simulates a cloth on a table or a flag moving under a wind flow? Cheers, SL

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Parallel computing MatLab Comsol

Hi, I am using Comsol 4.3 with Livelink for Matlab. I run an optimization code in Matlab where i call Comsol to perform frequency response simulations. Now i would like to start two parallel frequency...

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Automatic remeshing depending upon the gradient of the solution

Hello, everyone, I am solving a nonlinear equation on the plane. Its solution, u=u(x,y) is everywhere close to zero except for some region in the vicinity of the coordinate origin. This region is not...

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How to determine face numbers (using matlab livelink) associated with an object

Hello again, I am trying to 'automatically' set my boundary conditions for a model generated in matlab with livelink. I know which objects need to have which boundary conditions based on a draw order...

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Parameterise the position in a text file?

Hello, I want to use the 2D distribution of the relative permeability of a nonlinear calculation in a linear calculation of the same Model with same parameters etc. For that I export the data of the...

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Continuing Modeling Issues with 2D & 3D piezoelectric SAW model

Hello all, I’m in desperate need of help with my model. The initial model setup is a 2D cross-sectional SAW device where I have silicon, a metallic electrode as my ground, a buffer layer, a...

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Problem with 3D PDE thin layer mesh

Hi everyone I encountered a problem with meshing a thin layer(~10e-6m) with 3D PDE model. I am not sure how to mesh such thin layer. Has anyone managed to mesh a similar case? Looking forward to your...

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Eigenfrequency seems right, but displacement units are totally wrong.

Dear Comsol Community, in the model attached I have a 20 micron long beam using the Solid Mechanics module to get the Eigenfrequencies. I calculated them manually using Euler-Beam theory and the first...

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"Hinge assembly" problem

While going through the solved model 'hinge assembly' given in the COMSOL, I came across some difficulties. Actually, I have to develop a solid model involving hinge joint similar to what is provided...

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How to assign a defined function to an electrode????

Hello Friends, Am working on AC/DC Module and new to comsol. Am trying to define a rectangular pulse of 1200v with a duration of 1ns to an electrode and i wish your kind assistance for the same. Thanks...

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Which Lithium on battery is used in Lithium ion isothermal 1D comsol model

Who is the manufacturer? which model ? anyboby knows?

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