Post-process two different solutions from a Parametric Sweep...
Hello, I am using COMSOL 4.1 and I am facing a conceptually simple problem with no luck. Basically I have a simple 2D Eigenvalue Problem which gives me 20 eigenvalues (and 20 eigenmodes) and a...
View Articletumor ablation model
hello, i am trying to make a model like" tumor ablation" model in comsol Heat Transfer Module but i want to change the current from DC to AC current and i want to plot the electric field distribution,...
View ArticleMeshing Air
I'm new to 3D COMSOL and I have the geometry for a chamber that will have air running through it while it performs its function. I am easily able to mesh the geometry, but I'm having problems finding a...
View ArticleMultiple MEMS devices in parallel using electrical circuit physics ?
Hello, Here is my model: I am simulating a micro piezoelectric systems. The simulation is complex and can take some time. Then, I use the electrical circuit physics to simulate my systems with an...
View ArticleRecovering desired eigenfrequencies
Hi, I'm performing an eigenfrequency analysis of a model in the Comsol 4.3a RF module. My problem is that, though I ask for only 1 eigenfrequency, Comsol ALWAYS gives me 2 eigenfrequencies: one purely...
View ArticleError while solving Joule heating: mesh-case 0 there are 665 void equations...
Hi, I tried to simulate joule heating in a copper cylindrical wire with an cylindrical air-void in it. But I am getting following error: Failed to find a solution. Singular matrix. For mesh-case 0...
View ArticleCantilever Beam Rotation Measurement
Hello, I recently have developed a model of a cantilevered magnetorheological elastomer (MRE) that bends when a magnetic field is applied perpendicular to the magnetization of the MRE. I was wondering...
View ArticleCreate Probing Surface then Surface Integrate over it
Good evening Ladies and Gentlemen! I'm working with a 3D fluid flow model, and I want to find the mass flow rate through an arbitrary cross section of the flow. How can I create a surface that can then...
View ArticleInserting array in comsol model struct
Hi, I wanted to solve 2D Poisson's equation in a structure and for this, I need to update position dependent concentration array/matrix (rho) in the model. What is the syntax of using external...
View ArticleSolving a 4th order PDE: how to specify boundary conditions
A fourth order PDE like the biharmonic equation: ∇^4 w = 0 can be placed in Comsol's standard forms by writing u = ∇^2 w, so that we have system of equations:∇^2 v = w∇^2 w = 0 where v = v(x,y) and w =...
View ArticleFailed to evaluate variable: freq
Hi COMSOL Users, I'm new to using the v4.x series of COMSOL, so perhaps I've missed something simple, but I get an error when trying to plot body volume force variables. The error message...
View ArticleHeat transfer
hi, i need to calculate thermal conductivity for various volume fraction of ALN with PMMA. In that paper they mentioned about When the sample is given a heat power,the direction of heat transfer is...
View Articleboundary selection problem
Hi When I move the pointer to a certain boundary and click, an adjacent boundary lights up instead of the boundary I pointed at, how do I resolve this? thanks David PS this is a problem that suddenly...
View ArticleHow to extract solid deformation of a time point in a transient process and...
Hello, My aim is to make a simulation to observe the change of the optical phase on a optical fiber's outlet in a cycle of sound pressure. And I have a question as follow: In file.A, I use transient...
View Articlecalculate the radius of curvature in 2D model
Dear colleaugues, I was looking for ways of calculating the radius of curvature of a deforming boundary in 2D model (in time dependent solid mechanics module). i tried to use the equations derived for...
View ArticleMatlab function not working under linux
Hi all, I have trouble using Matlab function within Comsol (standalone), under linux. Half of the times I get the error message Could not Start Matlab () Library cscomsol.so The other half times comsol...
View ArticleNeed help: Error whenever trying to simulate periodic boundary condition in...
Hi Everybody, I'm trying to do 3D RF module simulation with periodic boundary condition on the sides. Every time i start the computation, i keep getting an error that says : Unknown function or...
View ArticleDahlquist Research Fellowship 2013-2014 Now Open
Hello, We are happy to announce that the Dahlquist Research Fellowship is now open for applications. Numerical analysts looking to do research are eligible to apply to this fellowship co-financed by...
View Articlematerial content section
Hi I have a problem,please help me in material content section i add refractive index for "sio2" but it don't have green mark.what can i do?
View ArticleHow can I simulate this problem??
I'm new to COMSOL, I want to simulate multiphysics(flow rate and electric field) but have some problem about meshing geometry. I use ITO electrode and water contain in the microchannel. ITO thickness...
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