Error to initialize a physics interface created with Physics Builder in...
Hi all, I am trying to compile with LiveLink for Matlab (Matlab version MATLAB_R2012a) a Comsol model (Comsol version COMSOL 4.3.0.151) that uses a physics interface which I created with the Physics...
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 ArticlePiezoelectric transformer interfaced with electrical circuit.
Hello, I have made a piezo transformer model and wish to drive it using an external electrical circuit interface. I have made connections to the electrical circuit elements using a voltage source, a...
View ArticleCOMSOL 4.3a Installation Problem
After installing 4.3a, whenever I open most files (or try to at least), I get the following error in a pop-up window:
View ArticleComplex permittivity in electric currents physics
This seems like a simple question but I can't find a clear answer in the documentation. I wish to solve for the electric field induced by a conductive particle surrounded by an insulating membrane in...
View ArticleTransient simulation output doesn't match input
Hi I'm simulating a 2mm radius magnetic loop excited by a transient current and surrounded by a 10cm air sphere, in time dependent study. I've interpolated a gaussian current input from several points...
View ArticleEvaluate the electrical voltage from the magnetic field (mf) physic
Hi ! I need to calculate the electrical voltage of an electric conductor subdued to a magnetic field. The conductor is excited by a current density using magnetic field physic (mf). I want to simulate...
View ArticleZero stress boundary
Hey everyone, I'm trying to figure out how to model and find the motional eigenfrequencies of a totally free cylinder. That is the requirement as I see it is to have zero stress on all surfaces while...
View ArticleMovement of air due to thermal expansion
Hi everybody! I'm trying to simulate the movement of the air in 2D and I only get errors. I use two physics: laminar flow with heat transfer. I've created a square full of air and I put easy boundary...
View ArticleUnsteady Analysis
Hi, I am solving unsteady state navier stokes equation with a volume force term. My volume force term contains a term like sin(t), now i want to make sure that the unit of angle in comsol is radians,...
View Articleerror in model library
Hi, guys. I am learm a model in model library , the name is "domain_activation_llmatlab.mph". I am doing the example step by step, but at last I find that i can't run the matlab code. There is a error...
View Articlecombination of convection and conduction help
Hello I want to analyze flat plate and air around the plate. Laser make heat on the plate. Air gun shot the plate for cooling. It happens in a big hexahedron. Above all, I want to know how to analyze...
View ArticleNonlinear free vibrations of beam(2D)
Hi I need to model free vibrations of beam with geometric nonlinearity rho*d2u/dt2 = A(u) where A - nonlinear operator, with some boundary conditions. Basically this problem is reduced to eigenvalue...
View ArticleCalculating EM Force in the Electromagnetic Waves (emw) Environment
Hi, This should be a very straightforward question. I would like to calculate the time-averaged electromagnetic force (via integrating the Maxwell Stress tensor over a surface). The fields that I need...
View ArticleUsing external file data for heat source
Hi all, I am trying to solve a model for heat transfer in solids using external data as heat source input. The geometric model is simple and composed of 3 separated bodies attached together by a...
View Articlephase transformation
hi everyone, I'm looking to modelize a phase transformation in the Titanium alloy ti-6AL-4V during the course of the beta-phase to alpha-phase. I'm not sure if Comsol can do that or not. If the...
View ArticleBaw Resonator Problem
Hi I am working on a baw resonator. For our simulation we have considered a 3.5a COMSOL 2D model of Thin Film Bulk Acoustic Wave Resonator in the model archives of COMSOL. So we treid to simulate the...
View ArticleTrouble coupling heat transfer physics for both fluids and solids
Hey all, So I'm getting stuck with my model where I try to couple three different physics. The three physics are: Electric Currents, Heat transfer in Solids, and Heat transfer in Fluids. Basically what...
View ArticleBoundary conditions in Equation-Based Modeling
I am trying to solve a set of three "Helmholtz-type" equations using the Equation-Based Modeling of Comsol. There are three independent variables, call them u1, u2, and u3. The equations are (with some...
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