Where to find the definition of "First principal strain" definition formula?
Hello everyone! I am using Comsol 3.5a. I have a question about first principal striain definition in Stucture mechanics module. From "Physics - Equation system - Subdomain Settings", we can see all...
View ArticleLivelink timeout issue
I am having issues with Comsol with Matlab. My loop keeps stopping and I cannot figure out what the problem is. I am clearing out the answer and the model after each iteration. The error is listed...
View ArticleIn parametric sweep, is it possible to use the eigenfrequency of last...
Hi, I'm doing a parametric sweep over some parameter (kx). For each value of kx, I trying to find one eigenfrequency. But my problem is that I want to use the solution for the previous value of kx as...
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 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...
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