Boundary current source vs electric potential source
Hello, I have a question about the AC/DC module -> Electric currents. I made a simple model of a spherical homogenous volume conductor. Inside this sphere I added a cylinder along the 3-axes. On the...
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 ArticlePolydisperse particules
Does anyone know how to implement polydisperse particles in the particule tracing module of COMSOL?
View ArticleUrgent: Eulerian mesh
Hi everybody, there is an euleriam mesh in Comsol.4 ?. If yes, can someone help me to know how can I use it ? thx in advance.
View ArticleMultiple-size particle tracing
Hello everyone I have a short question on the particle tracing module. Does anyone know that whether it is possible to simulat particles of different sizes in the same model. How to implement this...
View ArticleAbout coupling Richards Equation
Dear Sir: I want to coupling two Richards equation exactly on the same Geometry, to represent two different subsurface flow with different velocity, and define a function as a source sink term depend...
View Articlehelp me to find how to get exact values from model
Dear all , I simulated two coil system in induction coupling , and i define parameters and formulas in parameters section , but i dont know how to derive practical values by applying same formula in...
View ArticleSimulation error in time dependent study
Hi I'm closely following the built-in tutorial model "coil above plate", so I'm using the magnetic field (mf) physics with the single-turn coil domain and so on. The only difference is that I'm not...
View Articleproblems with a e.m. computation
Dear all, I would like to find the resonances of a ring resonator. I used a axisymmetric model (2D) with eigenfrequency analysis. The materials are air and a polymer for the ring. I put the PMLs but...
View ArticleHow to draw a hemisphere?
Hello friends, Am trying to draw a hemisphere,i drew a full sphere and tried to split but i cannot do it!!! Expecting your help. Thanks in advance.
View Article2D Electrode Model Question
Hello all, I am attempting to model the time varying current distributions on 2 rectangular electrodes with with tabs. The model idea is that current flows into one electrode through its tab, then...
View ArticleEquilibrium condition for an identity pair
Hi. I am new in COMSOL and I am checking for the software abilities. Currently I am using the identity pair in a mass transfer model. The idea is a fluid flowing on the surface of a slab, which is...
View Articledesign and analysis of mems piezoresistive pressure sensor using comsol
we are doing a project on mems pizoresistive pressure sensor .... we have created a model ... bt we are finding difficulties in giving pressure as an input .... please suggest .....
View Articlerelation between eigen frequency and pressure
we are currently doing a project on mems piezoresistive pressure sensor using comsol.... can you please tell how both eigen frequency and pressure are related to each other?
View Articlehow to plot the electric field y- component
Hi: I am trying to find how to show only the y-component of my electric field. I know that I can choose to plot any field component I want. I just lost the way to do this any help? thanks, Naema
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 ArticleChange 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 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...
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