Question 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 ArticleODE in comsol
How to solve this equation dM/dt= uM x Heff + vM x (MxHeff) where x=cross product u,v=constants Thanks in advance, Maha Please somebody help....
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 ArticleHow to debug MATLAB function (COMSOL 4)
I am able to declare MATLAB function in comsol. When I run comsol, it gives me error "Incorrect size of returned vector. 596 elements were expected, but the returned matrix was 1 x 1" The error is OK...
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 ArticleCluster computing got stuck :external progress scheduling
Hi,Ihave recently setup a cluster and i had comsol 4.3 on the head node,and i had the installation forder shared, model working directory shared. However,when I am trying to submit a batch job,using...
View ArticleMatlab function in Comsol handover String
Hi everyone, thanks to the discussion on www.comsol.com/community/forums/general/thread/7946/ I've successfully included a matlab-function with 3 arguments (equal to the tree dimensions of my problem)...
View ArticleNegative port impedance
Hi All, I am currently doing some antenna modeling. The antenna is excited by a 50 Ohm coaxial port. I get reasonable S11 results at resonance but the lumped port impedance is negative e.g. -5 Ohms....
View ArticleMixture Model, Laminar Flow (mm) interface - anyone using it?
Hi, I wonder if anyone here in the forum is using the Mixture Model, Laminar Flow (mm) interface. I have several issues when using this interface with a fully coupled solver (namely, singular matrices...
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 ArticleHow to display current density in thin metallic layer difined by transition...
Hi to all, I'm working with the RF module to simulate response of metamaterial which consists of split ring resonator (SRR). The SRR is made of thin metallic layer. To model the layer within Comsol I'm...
View Articleproblem in initial value in matlab
Hi I'm simulating a model in matlab for a sampling time 3 s. After this i use the last simulation as initial condition for the next iteration. I use the following code (as the tutorial): for k = 1:nit...
View ArticleAdaptive Mesh
Hi every body. I am simulating 2D level set two phase flow fluid in transient form. I would like to use Adaptive Mesh for my model. I tried alot for finding example and doc for that but I couldnt find...
View ArticleProblem with multislice view
Hi, I'm new in COMSOL and RF modeling so I started with building existing models from model gallery by following given instructions. At the moment I'm simulating model Biconical Antenna. The results...
View ArticleWhich Physics to choose?
Hello Friends, I am trying to apply voltage and wish to check the conductivity in the dielectric material, which physics should i choose??? Thanks in advance
View ArticleDiffusion problem
Hi friends I want to model a fluid (Air) from one side and gases (3 species i.e xenon,radon,helium) to diffuse from the bottom. the problem is when i select air for the domain for fluid flow and then...
View ArticleDemagnetizing field
Hello everyone, my goal is to observe the magnetic flux density in a gap of a toroid. I started with 2D at the beginning and was able to simulate my experimental setup. The destribution of my field...
View ArticleRefractive index change from electron/hole concentration in waveguide
Hi I am trying to simulate a wave guide electro-optic device/ switch and I need to perform the following steps. 1) Create an electrical model to solve for the concentrations of electrons and holes in a...
View ArticleMotion due to a magnetic field
Hello everyone, I am pretty new to COMSOL so this might be a simple question to answer. I want to 2D simulate the attraction between a magnet and an iron bead which are located in air (see attachment...
View Article