Problems related to relative tolerance and relative error
Hello I want to reproduce a model in which there are two spheres in contact one upon the other along the z axis, and then i has applied two forces, one on the top (point or boundary region of the...
View ArticleMarangoni Stirring / Phase Change: Weak Contribution Settings
Hi I have a problem with a weak contribution in a laser surface melting model: My model takes into account solid-liquid phase change using an enthalpy-porosity technique and liquid phase volume forces...
View ArticleMoving mesh ALE
Hi, I am simulating a moving boundary with ALE method. My program is working fine with a certain geometry, mesh and time, but if I would like to change the geometry or set a larger time, then I get a...
View ArticleDefine a function like Linear elastic-perfectly plastic behavior.
How can I define a load which increase linearly up to time t0 and then stay fix by time. I defined something like "F*(rm1(t<t0)+step1(t))" which step function location is time t0. the only section...
View ArticleComsol RF module norm and phase
Dear all, I have a problem with Comsol, a very naive one. I am trying to do a harmonic simulation (a single frequency in frequency domain model) of the EM scattering in a domain. For example if I have...
View ArticleSkull and Electrical Conductance
Hey, I'm just a beginner with Comsol and I'm trying to build a model of a human head that includes a top layer of skull, a brain, and space in between the two filled with some kind of conductive...
View ArticleDuplicate variable name
Hello all, I got some duplicate variable name error when computing my model(see the attachment), which including the piezoelectric device, laminar flow and deformed geometry. Should I use the physics...
View Articleco-efficient of thermal expansion
Hello evrybody, Can anyone help me to know if I can input my co-efficient of thermal expansion as a function of Stress and Temperature or not. And if possible how to do that. Thank you.
View ArticleOutput pressure of the transducer adding Vac + Vdc
hello, I 'm working on a capacitive transducer, using the electromechanics(emi) model. Now I want to observe the output pressure of the transducer in the frequency domain and I add a voltage V=Vac+50...
View Articleerror in statonary analysis of a biased resonator
Dear comsol community, I'm working on comsol4.2a , I would be glad if i can get a solution for my following two queries: 1) I have gone through the modelling instructions given in the 'Stationary...
View Articleplot
Hi I simulate the mode profile of the rib waveguide. Now i want to plot the normalised intensity(arb unit) in the x and y directions. Do you know how can i do this?what is the arb unit? how can i find...
View ArticleResonance frequency of beam (calculation+plot)
HI I want to calculate and plot resonance frequency of cantilever that I designed in MEMS module. Based on the previous discussions here I understand that I should do the study in "Eigenfrequency" and...
View ArticleOut of memory during LU factorization
Hi there, I am a new member in the COMSOL community. I am trying to solve a simple 3D problem having diffusion and chemical reaction within the subdomain. However, I am getting this message "out of...
View ArticlePiezo Loading
I have a 3D piezo model and the output is currently a floating potential. This tells me the theoretical unloaded voltage gain. I'm working on possibly using a global equation of a simple ohms law...
View ArticlePlacing a finite element model into an electrical circuit in COMSOL 4.1
Hello, I have recently made the switch from COMSOL 3.5a to COMSOL 4.1, and I am currently unable to do things that I used to be able to do very easily, namely placing my 3-D model (drawn and defined in...
View ArticleMark my experimental values to the curve point in the plot window of COMSOL
Hi Everybody The purpose of my question is to compare the theoretical curve obtained on COMSOL with my experimental values on the plot window. I have a curve point on the plot window. I have a few...
View ArticleAbout optical force calculation of particles manipulated by microring resonator
Hi,everyone. I want to simulate a structure which includes two bus waveguides and one microring resonator to form an on-chip optical tweezer. One microparticle is placed in the gap area between one...
View Article3D Poisson equation problem coupled with Nernst-Planck equation
I used coupled Electrostatics physics and Transport of Diluted Species physics to simulate this problem. The source term in Poisson equation is the difference between cations and anions. Usually, the...
View ArticleStructural Mechanics Equation System
I am trying to understand how my structural mechanics model is computing its solution. The model solves and gives me a reasonable solution. However, I don't understand how it is arriving at its answer....
View ArticleSloshing Tank with FSI
Hello All I calculate the waves of a water tank and then damp with a structure the waves. At the beginning I start with a single excitation an then wait and just let the gravity do the job. My model is...
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