Time Derivative Constraint
This is the matter: I'm modelling a Gleeble test: a bar is being heated by Joule Effect. Now I've tried to model a feedback loop control, I need to control the Heating Rate, the variation of...
View ArticleCalculating Shapefactor of a isotropical corner
Hello. I am relatively new with COMSOL and is thereby not that good with the different tools and methods in, which to find out different values etc. Currently am I trying to find out a shapefactor of a...
View ArticleBeam excited by a shaker
Hi All, I aim to model a simple beam excited by a shaker. I am using the Solid Mechanics. I would like to know how big is the displacement of a particular mode (eg first flexural) when I excite the...
View Articleproblems with an easy heat model
hello, I am starting to use Comsol and I have a problem with an easy model. I have a heat source, that have modelled as a box of copper, and a thin shell of aluminium with an small defect. I want to...
View ArticleLiquid Encapsulated Capacitor
I think I should first start with "I am extremely new to COMSOL" :) That being said, I started working with it a little and now I can finally design a capacitor and have COMSOL calculate the...
View Article2D Arrow Surface Plot -- Arrow Length Logarithmic
Hello, I am plotting a 2D Surface with an arrow surface. I need to scale my arrows logarithmically, but I am unsure whether this scaling is a natural logarithm or a base 10 logarithm. Which is it? The...
View Articlesimple solidmechanics
Hi I have a simple model that a piston presses down brain tissue. The piston moves with a prescribed displacement. A problem is that the piston always moved the same distance, even I have changed...
View Articlefind the coordinates of a point in which the magnitude of derived variable at...
Hello, I am working on a 2D transient problem. I have the results and want to post processing them. I want to plot my results like this: Detect the minimum of a derived variable all over the domain at...
View Articlelongitudinal waves/P-wave in aluminum plate
Hello people, Does anyone know how to simulate longitudinal waves in YAG or LiNO3? I'm completely new using comsol, Thanks
View ArticleModelling a Lumped Capacitor in COMSOL (Frequency Domain EM simulation)
Hello, I am trying to critically couple a resonator to a microstrip transmission line using a lumped coupling capacitor. Does anyone know how I can do this in COMSOL. I know it is possible in HFSS. Can...
View Articlev4.1 RF How to use two or more variables in parametric sweep
Hi I want to do parametric sweep that effects the geometry too. The first variable is the incident field wave length and second is angle of incidence. How to run these parametrics or how to run nested...
View ArticleError: Parameter lists gives empty sweep
Hello, I would like to know the reasoning behind this error in return of a monotonously incresing series of frequencies. Examples: a) 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 90,...
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 Articlerigid particle carried by a channel flow
Hi I have to simulate the displacement and rotation of a rigid prticule in a fluid flow and I am not a professional on comsol. So, is there anyone who could help me? or if you have any examples of this...
View ArticleOscillating electric dipole source Comsol RF module
Dear All, I have question. I do simulations of plasmonic gap nanoantennas, and I want to excite antenna with dipole source which is placed and oscillate in the middle of the gap. I have questions....
View ArticleConstitutiveRelationD error
Everyone, I am trying to add an external current density domain to my electric current (EC) simulation. However, when I try, it says that there is some sort of "ConstitutiveRelationD" error. Has anyone...
View ArticleDye oscillator, please help
Hello! I model Dye oscillator ( rspa.royalsocietypublishing.or...tent/155/886/498.full.pdf+html ) in Comsol. The frequency of a ring oscillator is supposed to be the wave speed through the quartz =...
View ArticleSimple example to solve ODE
Hi, I am a complete newbie with COMSOL (I have the MultiPhysics module, version 4.3a), and I have only followed some initial tutorial examples in the manual (e.g. "the wrench"). However, as I...
View ArticleInitial negative concentrations
HI All, I am trying to simulate a A+B-->C chemical reaction. I dont know why my reactants (A and B) concentration is going negative. How do I fix this? I have attached my model as well as pic of the...
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