Defining MIXTURE of gases
hi friends i want to define a mixture of gases (iodine,xe,radon) at inlet each with different concentration for diffusion in the air . how can define mixture with different conc in comsol .
View ArticleMembrane Deflection ( Measure displacement)
Hi, I am very new to comsol. I have been trying a few simple models. I have a simple model of a membrane (2d axisymmetric, attache is an image). I just want to measure the displacement (maximum) from...
View Articleregarding coupling of physics
What is the difference between fully-coupled and weak-coupled. can any one explained through example by taking multiphysics problem.
View ArticleConvergence problem
Hello to all, I'm trying to simulate signal transfer through human arm. At the moment I'm facing convergence problem and I really don't know what to do. I tried to change model boundary conditions and...
View Articlepde_bimodular materials
Hi,I'm a Comsol newbie. I'm trying to create the model of a beam made of a bimodular composite material. Where the material is compressed(eg. d(w,x)<0) the elastic modulus Cbm will be...
View ArticleModelling and simulation of the ultrasound propagation at the interface...
Hello, I am trying to understand how Comsol works. I don't know to work with this program. I've received a homework and I am trying to model the ultrasound propagation at the interface deposited...
View ArticleUndefined value found in the stiffness matrix.
Hi I am Getting Following error when I am trying to solve Mosfet model in comsol Undefined value found. - Detail: Undefined value found in the stiffness matrix. .There are 9 equations giving NaN/Inf in...
View ArticleSimulation of a pull-out test giving error.
I am trying to verify the experimental results of a pull-out test using COMSOL 4.2 But I am getting errors. The geometry is as follows: A cavity is made in a cylinder made of concrete. Now a steel bolt...
View ArticleParticle tracing in COMSOL 4.2
Hi all! Does anybody have negative experiences with particle tracing in COMSOL 4.2 (and NOT 4.2a)? Because I do. COMSOL simply fails to trace small particles in even very simple situations. I placed a...
View ArticleCircuit terminal question
Hi, All, I'm trying to build a model four terminal nodes. Two of them are COMSOL voltage (terminal 1) and ground (terminal 0), another two is connected to 'external' resistor which is not defined as...
View Articlepiezoelectric
If i connect a capacitor I got the error message Errors during multiphysics The DAE is structurally inconsistent. - Variables: 2 - Equations: 1
View Articleinterpolation function
Hi, I have a problem with the interpolation function. I want to use a spatial (x,y) interpolation function for me conductivitu in the model. I import a spreadshit in the format of: % Description:...
View ArticleCircuits to coils
Dear All! I'm working on a wireless energy transfer project. I created a model in Comsol 4.2a. I attached the files. My questions are the following: I did my modell with a 2D asymmetric system, I...
View ArticleStop Joule heating and start cooling.
Hello, I am trying to simulate Joule heating model in Comsol multiphysycs heat transfer module. I want to use joule heating till the 19 sec. After 19 I want to stop JH and continue convective cooling...
View ArticleFuel tank simulation
Hi, I have a project about fuel tank simulation. The thing that I try is similar to the sloshing tank example. However, since the fuel tanks are closed [ :) ] I need to limit the deforming mesh. Has...
View ArticleCan't use variable defined in 'Global Definitions' within a Waveform definition
I have defined 'tau' in Global Definitions as a variable = 40000*3600*24*365.25[s] I have created a Waveform also in Global Definitions (and in local definitions just to check), with angular frequency...
View ArticleAttributes for each region, integration over region
Greetings, I am new to Comsol and tried to see if a similar discussion has been carried out before without luck. I have a magnetostatic model with several regions (windings). I need to connect...
View ArticlePrincipal stress 2d vs 3d
Hi everyone, I have the same model made in 2d and 3d. First and second pricipal stresses are similiar in both models. But third principal stress in 2d are unrealistically high, however in 3d have value...
View Articlevibrating rod
Hi, I have a coil and inside a rod. The rod vibrate with a given frequency. Knows somebody how could this in Comsol ? In help are some materials about vibrating membrane but I don't know exactly to...
View ArticleRelative Tolerance
Hi I have done some simulations and the intial values used are the default ones. I was wondering when does initial values are important? Is it important to set the relative tolerance for a problem...
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