Need 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 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 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 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...
View ArticleProblem with magnetic damping model
Hello Sir I am working on magnetic damping model given in your tutorials but while giving details it is showing some errors which i am unable to resolve i am attaching a file please help me in...
View Articlehow to use the heating result as the initial value of cooling in another solver
hi i model a heating process,and use its temperature field as initial to model the cooling ,with many trials, i find the cooling initial temperature differ from the heating one ,so what i should do...
View ArticleNo convergence
Hi I am solving Nernst-plank equation for electrochemistry. During the solving massage comes:"No convergence, even when using minimum damping factor" or " the value is more then tolerance limit. This...
View ArticleThin film joule heating
Dear all, I'm interested in whether I could apply an thin film joule heating approximation to model an MEMS heater. (Dimensions are 200nm x 0.025mm x 2.5mm on a 1um substrate.) I've got the thin film...
View Articlegrid control
Hi, I am trying to plot a graph using the 1D plot Group and Line Graph, but I want my graphs to appear with the background grid invisible but I can't find an option to remove the grid from the graph....
View Articlesinusoidal voltage to time dependent solver
I am trying to apply sinusoidal voltage to a model with time dependent solver. I apply the voltage based on a function but it doesn't show anything. the model is attached. thanks
View ArticleMetal film with subwavelength size hole: Transmmittance and reflectance study
Hi I'm novice in comsol RF simulation. I'm trying to simulate transmittace and reflectance throught metal film with subwavelength size hole. My structure will consists of Air/metal/semiconductor...
View ArticleTest function for Electric field
Hey all I am working in the 2D piezoelectric module and I want to take weak forms of Electric field in different direction, test(pzd.EX) and test(pzd.EY) but its showing error. When I try by making the...
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