Change boundary conditions during a transient solution
Hello, in an acousitc transient simulation, I would like to change a boundary condition during the simulation. I would to impose on this boundary: 1. a pressure condition during the 100 first time...
View Articleconfinement loss
Hi is imaginary part of refractive index could be positive or negative that means 1.028175433939737e-19 or -1.028175433939737e-19. I found in my simulation positive and negative values for different...
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 ArticleModel extrusion coupling Help
Hi, I need help in resolving an issue with my model. I have a number of ODEs of the form; dA/dt = A + B domain 1 dB/dt = B+A-C domain 2 dC/dt = C+A domain 3 Each time I try to solve the problem, i keep...
View Article4.3a not starting in Win7 64bit
I have a problem with the Comsol Multiphysics 4.3a. I double-click the icon on the desktop, and the startup screen pops up. But after a few seconds, it closes down and nothing more happens. I have run...
View ArticleChemical Reaction kinetics, error
Hi, this is my first try on Comsol, I am modeling the reaction kinetics of a monolith reactor, using plug flow model for a single channel. there are 3 reactions and 8 components. 2 reactions are at...
View Articlehelp please with initial conditions
Hi, can anyone please answer me? I really need help! I am tring for a while to work a problem I have and I need help. I have a running model (on the comsol-matlab interface) of electric current. the...
View ArticleElectromagnet in 3D
Hi!! I am a new user to comsol and electromagnetics domain. As a first step, I scanned through the models in model library in order to find the required modules for my geometry. I' ve sorted out much...
View Article3d Core, Error: Unknown function or operator
Hello, I have modeled a 3d core with a coil and the coil I have declared Muti-turn coil. And in the simulation I have the following error: Unknown function or operator Name: mod1.mf.mtcd1.intp_edge...
View ArticleFrequency Domain Analysis
Hi, I am trying to simulate a 3-D beam in COMSOL v4.3. This beam is free in one end, and in the other end, I want to applied a sinusoidal boundary displacement input D(t)= Damp*sin(2*pi*f*t). In the...
View ArticleMixture Model, Laminar Flow (mm) interface
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 ArticleCan I use 2D boundary condition?
Hi, I am trying to simulate the concentration distribution of reaction with known boundary condition. If I know the concentration on the each spot or pixel of boundary at any time, how can I pass the...
View Article3D fluid flow in a pipe
I am trying to model laminar flows being joined as a number of pipes are joined. I also care about the thermal effects, so I need to model the pipes as well as the flow within them. However, I can't...
View Articlehygro swelling
hello everyone. i'm a newbie on comsol. just would like to ask if anyone knows where i could find physics on the hygro swelling component of COMSOL. i have tried already to run thermo induced stress...
View ArticleCoupling to a ring resonator
Hi, I am having trouble with coupling from a waveguide to a ring resonator. Light is guided along the waveguide however it is not coupled to the ring resonator (the gap is close enough). How should I...
View ArticleHow to calculate Extinction efficiency in comsol35a?
Dear Users, I am new to comsol. I have tried the example of a gold nanosphere in RF module. I have obtained directly the scattering cross section, extinction cross section and absorption cross section...
View ArticleConversion: Comsol mesh to Comsol geometry
I have a question concerning the possibility to convert Comsol mesh to Comsol geometry. For instance, I have a Nastran surface mesh which has been imported into Comsol mesh but I would like to use this...
View ArticleParticle tracing, how to release particles?
Hello, I am using the particle tracing module in comsol 4.2 to track charged particles in an electric field in 3D geometry. I basically need to release particles from the top plane of a cube and tract...
View ArticleSolving Self - Consistent Schrodinger and Poisson with MATLAB and COMSOL...
I'm a COMSOL 4.2a user. I need to solve 2D self-consistent Schrodinger and Poisson equation. Thus, I need to feed the potential values and the wavefunctions to the Schrodinger and Poisson equations as...
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