Heat source
Hi all, I have a model composed of three layers, three different materials. How could I insert a triangular power profile(as heat source) in the second domain. Example of power profile ( t=0s P=0w;...
View ArticleNegative port impedance
Hi All, I am currently doing some antenna modeling. The antenna is excited by a 50 Ohm coaxial port. I get reasonable S11 results at resonance but the lumped port impedance is negative e.g. -5 Ohms....
View ArticleCounter_driven_ coils
I'm new to COMSOL and I'm trying to model the b-field lines of a copper coil matrix and its interactions with an inert copper plate. I've been able to build a geometry and mesh however I've confused on...
View Articlematerial orientation for anisotropic material
Hi, When I tried to add let say Silicon to my 2D model (with x- and y- axes), there are varies of orientations to choose: <110> axis;<100>axis etc... Does the material orientation that i...
View ArticleIdentifying the eigenfrequencies of a shell sphere
Hello, I am new to Comsol and I was asked to identify the eigenfrequencies of a hollow sphere of 100um diam. and about 3 um thickness. I started by using 2d axisymmetric analysis->solid mechanics...
View ArticleTime Space dependent Interpolation function
Hello! I want to use a velocity boundary solution u(x, t) from one physics in another physics. The timesteps, the mesh and the geometry are equal. I use the Laminar Two Phase Flow, level Set physics in...
View ArticleDefine a Mixed (cauthy) boundary condition for Richards Equation(subsurface...
I read some paper, in the old version of COMSOL, we can choose a Mixed boundary condition (mix of Dirichlet, Newman and Cauchy conditions). in order to automatically transfer the boundary condition...
View ArticleConjugate heat transfer pipe flow
Hello, I am trying to simulate a very simple laminar flow inside a pipe problem with a constant temperature at the walls. I have a cylinder made of water(liquid), and where one part is kept at a...
View ArticleInstallation problems on Ubuntu 11.04: Failed to load libjvm.so
Hi, I have problems installing COMSOL 4.2a under Linux. I mounted the .iso file as indicated, but when i run setup, i get the following error message: Failed to load the JNI shared library...
View ArticleFinding the location of the maximum of a variable
Dear Comsol Community, I am looking for a way to find the location of the maximum of a variable. Getting the maximum value is easy, but so far I have not been able to get the coordinates of the...
View ArticleProblem: Oil Droplets Seem To Dissolve In Water (Two-Phase Flow, Level Set)
I have a problem with my "Two-Phase Flow, Level Set" simulation in COMSOL 4.2. I am trying to simulate the formation of oil droplets in water by hydrodynamic flow focusing. The water and oil are...
View Articleimport 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...
View Articlecan extract such kind of coordinations to build the model?
Hi, everyone, I’m building a heat transfer model, so the dependent variable is the temperature T. During the model, I want to obtain the location or coordination (x,y) where the temperature is equal to...
View Articlenon uniform heat flux
Hello all, I'm trying to model simple 2D conduction model in a slab. What I want to do is use a non-uniform heat flux for a boundary condition. I already have the heat transfer coefficient distribution...
View ArticleComsol on-screen font
Dear Comsol users Is it possible to increase the Comsol interface on screen font size? Thanks for hints.
View ArticleStop condition expression
How do I set up the stop condition if I want the solver to stop when the point probe expression ppb1 is less than a value?
View ArticleHow to change font size in the help of Comsol?
Hi, I am using Comsol Livelink for Matlab and I open the Comsol help from Matlab (using 'mphdoc' command). The help browser that I open looks exactly like the help browser of Matlab and even give as...
View ArticleDefine a selection from the solution
Hi, I am solving a two-phase system and I want to know, how can I calculate the time-dependent rise velocity of the bubble (in the file below)? In my case the domain selection is not possible because...
View ArticleContact Pairs in Solid Mechanics
Hello, I'm implementing a model about a sphere of a linear elastic material being squeezed between two plates (lower plate rigid, upper plate moving downwards). To consider the deformation of the...
View ArticleEditing Heat source equation in 4.1
Hello, I have to heat a solid 5mm diameter sample using laser. I was succefull in siulating a source at the surface and ged a good temperature distribution. But I would like to include another term....
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