stability of geometry creation
Suppose that the geometry is not simple enough to be represented by regular geometry primitives. Then, there are two chooses: 1- use of parametric surfaces (possible as external function) 2- use of...
View Article2D electrostatic Force
Hi, I am modeling a slice of a simple comb capacitor in 2D. I would like to determine the force acting on the fingers. I can calculate the electric field, but when I try to determine the force through...
View ArticleUsing the Optimization Module for geometry examination
Geometry optiization 4.3a Simple 1D sold state battery problem (in COMSOL) Done with assistance from COMSOL M = length of anode 320 nm L = length of solid electrolyte 1500 nm objective function =...
View ArticleUndefined 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....
View ArticleAdding temperature varying with time
I want to enter temperature for calculating heat flux (temperature varies with time). Is there any method of entering the values? How can I use functions like interpolation, Rectangular etc,,,
View ArticleJoule Heating - Study help
Hello all, I am currently working on modeling the thermal stresses of a surface mounted component on a PCB. However, i am currently struggling to get the physics to work. I have followed the available...
View ArticleCOMSOL 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. -...
View ArticleBoundary condition for finding the Eigenfrequencies of a simple cavity in RF
Hi, I'm trying to find the eigenfrequencies of a simple cavity in 2D/3D. I put my cavity in a large circle/sphere. now to find the eigenfrequencies, i put the scattering boundary condition for the...
View ArticleSetting 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:...
View ArticleWhy 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...
View ArticleHow 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.
View ArticlePostprocessing 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...
View ArticleParticle 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...
View ArticleComsol on HPC server
I have just set up Comsol on a 48 processor machine using HPC server it is one machine with no cluster. It is running extremely slow. When using all 48 processors it takes over 137 seconds to process...
View Articlewhere can I find the user guide for "Heat transfer module" and "joule heating...
Hi guys, just wondering where can I get the user guide of "Heat transfer module" and "joule heating module"? Electronic files will be better. I do have it for v 3.5, but as the software upgraded to...
View ArticleAutomatic 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...
View ArticleHow 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...
View ArticlePressure 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...
View ArticleParameterise 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...
View ArticleContinuing 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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