Define 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 ArticleHow to display current density in thin metallic layer difined by transition...
Hi to all, I'm working with the RF module to simulate response of metamaterial which consists of split ring resonator (SRR). The SRR is made of thin metallic layer. To model the layer within Comsol I'm...
View ArticleProblems using Electric Current for Nonlinear 3D semicondutive materials
Hi everybody, I am now using Electric current mode to calculate the electric field in an insulation structure including semi-conductive material in 3D domain. Comsol can not run and has a singular...
View ArticleNatural Free Convection
Hello, I'm attempting to model the temperature rise above ambient over the period of one day within a sealed concrete trough buried in soil with its top exposed to outside air. I have successfully...
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 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 ArticleProblem about Joule heating and thermal expansion
Hi I want to inject ac current (amplitude is fixed) to a silicon beam and hope to see maximum expansion when the ac frequency is at half of the mechanical resonant frequency of the beam. I tried using...
View ArticleConjugate heat transfer Interface boundary condition
Hello All, I am new to COMSOL. I am trying to solve a 3-D conjugate heat transfer problem with volumetric heat generation in the solid domain. The problem is more like solving for a temperature profile...
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 ArticleExtract Data from a Parameterized Surface
Hello, In my comsol model I would like to extract the electric and magnetic fields on the surface of a sphere. What I do now is the following: 1) I define a Parameterized Surface in the Results>Data...
View Articlebuilding piezo ring projector (electroacoustic transducer)
Hello, I plan to build piezo ring projector, but I don't decide to build it as 2d axis symmetry or entire 3d model. My electrodes would be located circumferentially. 2d model would be problem because...
View ArticleHow to set the time step dt to a specific value when calculating for...
Hello everybody, I am now simulating a transient problem using Electric current mode but I do not know how to set up the time step dt to a specific value. Anybody have experiences about this, please...
View ArticleAngle of incidence, RF modul, Comsol 4.2a
Dear All, I have issue. I have one metal block on substrate, and I want to illuminate it but at some angle (picture). One half sphere is substrate, one half air. Now I want to apply x polarization,...
View ArticleCan I do Cluster Computing in Trial Version of 4.3a
I have been trying to do cluster computing after adding a parametric sweep successfully in trial version of 4.3a. The advanced study options is selected and in the job configurations, i could not find...
View ArticleParticle tracing and DEM simulation
Hi All, I want to use the Module of particle tracing to do the DEM simulation. However, there are two major problems, one is the wall condition, the other one is the interaction between particle. In...
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