non uniform heat flux
Hello all, I'm trying to model simple 2D conduction model in a slab. What I want to do is use a non-uniform heat flux for a boundary condition. I already have the heat transfer coefficient distribution...
View ArticleComsol on-screen font
Dear Comsol users Is it possible to increase the Comsol interface on screen font size? Thanks for hints.
View ArticleStop condition expression
How do I set up the stop condition if I want the solver to stop when the point probe expression ppb1 is less than a value?
View ArticleHow to change font size in the help of Comsol?
Hi, I am using Comsol Livelink for Matlab and I open the Comsol help from Matlab (using 'mphdoc' command). The help browser that I open looks exactly like the help browser of Matlab and even give as...
View ArticleDefine a selection from the solution
Hi, I am solving a two-phase system and I want to know, how can I calculate the time-dependent rise velocity of the bubble (in the file below)? In my case the domain selection is not possible because...
View ArticleEditing Heat source equation in 4.1
Hello, I have to heat a solid 5mm diameter sample using laser. I was succefull in siulating a source at the surface and ged a good temperature distribution. But I would like to include another term....
View ArticleError Message "String index out of range: 66"
Hi Everyone, I'm wondering if anyone has ever gotten this message in Comsol and what exactly it means (I'm using version 4.3). I'm getting the error message when I try to run a parametric sweep. I'm...
View ArticleExtract Data from a Parameterized Surface
Hello, In my comsol model I would like to extract the electric and magnetic fields on the surface of a sphere. What I do now is the following: 1) I define a Parameterized Surface in the Results>Data...
View Articlebuilding piezo ring projector (electroacoustic transducer)
Hello, I plan to build piezo ring projector, but I don't decide to build it as 2d axis symmetry or entire 3d model. My electrodes would be located circumferentially. 2d model would be problem because...
View ArticleHow to generate a plane wave from "surface current"
Hi all, I'm currently doing a simulation about the photothermal effect of nanoparticles. I'm planning to repeat a simple example in the reference (pubs.rsc.org/en/content/articlepdf/2012/lc/c2lc40495h)...
View ArticleBeam deflection
Hi, I am using a electric field to pull in a cantilever. It is supposed to be a first step of using comsol. So everything works fine as long as i don't involve a moving mesh. I get an "Duplicate...
View ArticleHow to set the time step dt to a specific value when calculating for...
Hello everybody, I am now simulating a transient problem using Electric current mode but I do not know how to set up the time step dt to a specific value. Anybody have experiences about this, please...
View ArticleProblem about Joule heating and thermal expansion
Hi I want to inject ac current (amplitude is fixed) to a silicon beam and hope to see maximum expansion when the ac frequency is at half of the mechanical resonant frequency of the beam. I tried using...
View ArticleConjugate heat transfer Interface boundary condition
Hello All, I am new to COMSOL. I am trying to solve a 3-D conjugate heat transfer problem with volumetric heat generation in the solid domain. The problem is more like solving for a temperature profile...
View ArticleSphere-Sphere Forces
Hello. Firstly, greetings to everyone, I am new here. So, I am trying to build a model based on this article:www.google.com/url?sa=t&rc...mp;sig2=HC5XPGRvo0qippVGnfngLg I am also new to...
View Articleusing a time dependent function
Hi I'm trying to use a time dependent boundary condition with matlab. I need to simulate a boundary condition that change in a fixed sampling time, for example, every 15 seconds the value in the...
View ArticleQuestion about the triaxial test
I have a problem about the example in the model library. There is a step in the example, which i don't understand. Integration 1 1 ) Right-click Definitions and choose Model Couplings>Integration. 2...
View ArticlePiezo actuator in Fluid
Hi i want to simulate MEMS resonator with Piezo actuator in Fluid in COMSOL 4.3,but i don‘t know,how could i Piezodevice coupling to Fluid.Which ”Physics“should i use？Fluid-structure-interaction？
View ArticleSolve files in sequence
I have 5 different files that I would like to solve, each with slightly different parameters. Is there a way to tell COMSOL to solve a sequence of files and save the results so I can walk away and...
View ArticleCacluate power exchanged between solid/fluid and solid/solid
Dear all, I've solved a coupled linear elasto-acoustic model using COMSOL's Acoustic-Solid Interaction module. During the post-processing I would like to calculate energy balances to better analyze the...
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