Oscillating boundary condition
Hi, How can we impose oscillating boundary condition in terms of velocity, on a boundary of a defined geometry. Thanks in advance Saurabh
View ArticleWhy does COMSOL lead to zero solution for a high-order PDE?
Dear all, I'm trying to solve a system of PDE, where the highest order is 4. COMSOL supports finite elements of 5th order. So solving the equation system should be possible by using COMSOL. But the...
View ArticleUnits in global ODEs
I am creating a model that uses global ODEs to provide values for boundary conditions for a domain-based PDE model. The PDE model variables can be fully populated with units but the global ODEs appear...
View Articlewhere can we find the parametric symbols of different variables????
Hello Friends, Am a beginner to Comsol Multiphysics and i find difficulty in knowing the parametric symbols being used in modeling!!! Thank you.
View ArticleWarning in meshing!!!
Hello Everybody, I tried to simulate a 3D problem in electrostatics and found the following warning message under meshing,"face is much smaller than the specified minimum element size". Please help me...
View Articlewhy my model works on Mac OS but not Win 7 64bit
I have a very funny situation in the coupling the fluid flow with moving mesh and transport of diluted species. It works very well with macbook air 2011 version but not with my HP PC workstation 8gb...
View ArticleHow to model adsorption on a solid surface for a 1d stationary model
Hello, I created a 1D, stationary model using the Diluted Species Interface to model the diffusion and reactivity of several species within a diffuse layer adjacent to an electrode surface. Now I am...
View ArticleHow prevent an object from penetrating another object?
The attached file has a simple case that is a precursor to what I really need to model. The simple case consists of a membrane (hyperelastic material model) with a small quartz bead located a short...
View ArticleTrying to combine data tables into one to do multiple plots on the same graph.
I have two tables, and a plot associated with each. I want to plot the data in the tables on the same graph. Therefore I am trying to combine in the tables to plot the data on the same graph. But it's...
View ArticleFactor in error estimate and Tolerance factor
Hi, I am new to comsol. I was using fluent, but could not get things done there. Now when i start using comsol, i try to link things to fluent inorder to understand. In fluent while solving, we give...
View ArticleMultiple input ports in RF problems
Hello, I'am doing a simulation with RF module. It's about the mode analysis of a rectangular silicon waveguide. There are two waveguides. To propagate the monochromatic light of 1550nm (1.935e14 Hz ),...
View ArticleCoordinates in mapped system, expressions (X.Y.Z)
Hi there Im student, and working now on SAW Pressure sensor My PC have 4Gb RAM and I cant use 3D for this modeling. only 2D So, my surface material is ST cut Quartz, Euler Angles is (0;132.75;0),...
View ArticleNVIDIA driver 305.93 causing erratic behavior
COMSOL was working great until I got a Tesla NVIDIA GPU. After installing the driver NVIDIA 305.93 I started getting erratic behavior when mouse clicking on the graphics. When I click to highlight a...
View ArticleSurface evaporation, condensation
Hi, I want to model surface evaporation from a water flow at 40 Celsius and observe the consequent condensation on a cold surface. Can you help me with the model that I should use? I could not find...
View ArticleFace and edge selection broken in 4.3/4.3a on NVidia/OpenGL
Continued from other thread:www.comsol.com/community/forums/general/thread/32259/ The other thread was marked as "Solved", but it's not solved (using software rendering is not a sufficient workaround),...
View ArticleHeat Transfer in Soils
Hi, I am a comsol user and I want to have a 2d axisymmetric model. In my model, I have a soil sample that I put a steel bar in the soil. I want to heat the steel bar with a constant temperature 500(k)...
View ArticleThermal Conductivity as a function of temperature
Hi all, I am trying to include thermal conductivity as a function of temperature in my model but its giving me error 'inconsistent unit'..let us say the function is -1.27E-9*(T)^3+8.09E-6*(T)^2-...
View ArticleProblem with Modeling a multi-stage agitated vessel
Hi all, I am having problem getting my model to run and converge. I am trying to model a six-stage agitated vessel in 2D. I have followed the steps described in the posted modeling of baffled mixer...
View ArticleHagen-Poiseuille Flow
I am having problems getting the same result when I try to model the Hagen poiseuille flow as when I calculate it. For more information on Hagen-Poiseuille...
View ArticleSetting initial values for an iterative solver
Comsol user interface shows some options for setting initial values at the stationary study step at 'Initial values of variables solved for'. These are either zero or a solution - but we want to set...
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