How can I find eigenmodes propagating in given direction?
Hi! I have a general question about eigenmode problem in RF module. How can i find only eigenmodes propagating in given direction? For example, let's consider an infinite number of parallel cylinders...
View ArticleMoving mesh - Particle moving through fluid
Fellow COMSOL enthusiasts, I am trying to get familiar with COMSOLs moving mesh feature, starting with a really simple example: a particle moving through fluid (e.g. Stokes flow around a sphere)....
View ArticleChange the YOUNG’s modulus
I'm running this coupled heat transfer-structural model .The analysis is time dependent. In my model ,as the temperature rising, the metal has deformed (such as swelled).But in reality,the metal could...
View ArticleHow to define the zero potential at infinity boundary in electrostatisc of...
Hi, all I am not very familiar with COMSOL, just begin to learn, Looking forward to your help to address the issue "How to define the zero potential at infinity boundary in electrostatisc of ADDC...
View ArticleMissing geometries in a 2D plot group
Hi, My modell consists of a magnet between two ferrous pole shoes. In the air gap between those pole shoes is a ferrous triangle. I'm using the live-link interface to import this geometries from...
View ArticleEquilibrium composition
Can anyone help me solve this problem. I am not sure what I am doing wrong here. CH4 + CO2 <=> 2 CO + 2 H2 (equilibrium reaction) Assuming batch reactor constant volume and initially we have 1...
View Articlecontact plate element
Hi I have a problem how to model the contact between two plates en 2D, I need to know the conditions of contact between these plates (friction- sliding) these plates are modeling by their midlin plan,...
View Articlefinding capacitance
This is my first simulation in comsol . i don't know too much about this software.I am trying to find capacitance of a nano-FET in electrostatics module.for fringe field device is surrounded by air....
View ArticleFixed amount of confined fluids in presence of electric and magnetic field
Hi everyone, How can I apply electric and magnetic field on a fluid which is deposited on a plate and there is another plate at a some distance d apart from surface of liquid. (air above the fluid)....
View Articlesection view
I want to view a section through my geometry once the analysis has run. How to I go about this? Thanks, Christabel
View ArticleProblem: Cylinder appears to be block
I am quite new to this program and I tried to do create a 3D circular duct. I selected Cylinder and chose a radius of 0.004 m. In case of a short height compared to the radius, the cylinder keeps its...
View ArticleEquation editing in Structural physics in Comsol 4.0
Hi Everyone, I was exploring comsol 4.0. I found that the GUI is good but some functionalities in 3.5a are removed. I wanted to edit the Structural physics equation system to suit my PDE. In comsol...
View Articlehow to apply AC voltage
respected sir i m creating a mems based disk resonator on comsol4.1 structure is drawn and i need to apply a AC VOLTAGE OF 2mV TO ONE OF THE ELECTRODE IN MY STRUCTURE. can anyone help me how to apply...
View ArticleEditing equationin at Expression in Variables from Equation views
Hi all, I’m playing with thermo-mechanic coupling. In the mechanical part, I use solid mechanics with Norton Creep. In this creep, I would like to have nD=1. That’s why I’ve changed Expression in...
View Articlejava.lang.ClassCastException when using LiveLink from MATLAB
Hi there, I've been successfully using COMSOL and LiveLink for a few months now for generating and simulating electromagnetic models. However, yesterday I ran the same MATLAB code as I always do, but...
View ArticleEmpty parameter list
Hi everyone, I'm beginner to COMSOL and I'm modeling hyperthermia cancer treatment with magnetic nano particles. I'm using bioheat transfer for the body cells, mixture model for modeling nano particle...
View ArticleWill the increase of the relative tolerance reduce the solving time ?
Dear all, as mentioned in the title, I would know if the change (specifically an increase) of the relative tolerance in Time Dependent solver (but also in Stationary solver, why not) will reduce the...
View Articleelectrostatic potential induced by charges
Hi, I am fairly new to comsol, your help would be helpful, I have an electrostatic model composed of two electrodes and medium( air, plastic), just like an parallel capacitor. In my 2D model, I built a...
View ArticleNormal flux = 0
After update to 4.3b a new feature emerged: the normal flux at an electrode (viz electric current), for example, is always zero. If my electrode happens to be parallel to xy, xz or yz plane, I can...
View Articlesine waveform
Hello Please help me, my model is a electrode in a cylinder of tissue. i want to put a AC voltage on the electrode. i defined sine waveform (wv1) from (global definitions> functions> waveform)...
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