Unsteady Analysis
Hi, I am solving an Unsteady state problem, in which the time interval is very large, so it takes time to solve it. I interrupted the solution in between cause i saw the time step that i used to...
View ArticleMaxwell stress tensor integration
Hi everyone! I'm still trying to compare the electrostatic force calculated by the expression (F=0.5*epsilon*V^2*A/g^2) with the result coming by Maxwell stress tensor in COMSOL. I used the suggestion...
View ArticleTransient simulation output doesn't match input
Hi I'm simulating a 2mm radius magnetic loop excited by a transient current and surrounded by a 10cm air sphere, in time dependent study. I've interpolated a gaussian current input from several points...
View ArticleMie scattering in 4.3
Hello, I have already seen some discussion about mid scattering of a gold nanosphere. But I the discussions I have consulted, no one has yet implemented a mie scattering program in Comsol 4.2 or 4.3...
View ArticleWhat type of boundary conditions to use for a part of electric chain
Hello, I'm not really good with DC, but I have to solve one problem connected to it very closly. I have a model of a bimetallic Copper-Aluminium conductor. I know, that the value of generated current...
View ArticleURGENT!!ERROR
Hi!during the simulation an error appears: Failed to find a solution: In segregated group 1: The relative error (0) is greater than the relative tolerance. Returned solution has not converged. What...
View ArticleReflectance / Transmittance calculation using PORT
Hello all I want to calculate effect of nanostructure on reflectance and transmittance. As a starting point, I have refered "Fresnel equation" library. Without any nanostructure, the calculated...
View ArticleBig problem--- Microring Resonator
Hi,everyone, I built a 2D micro-ring resonator model which stated in one publicated paper. I check all the parameters I set are same as the paper mentioned. But the problem is , even in the ring, no...
View ArticleComsol 3.5 and Matlab - boundary ID
Hey, I have big problem with Comsol Script. At work we just have the very old Version 3.5 - the new one we will maybe get during this year but I cannot wait until this future-date! I have a geometrie...
View ArticlePredefined rigid body movement in a laminar flow
Hi, I want to model a predefined rigid body (cross-section of a bridge deck) movement in a laminar fluid flow. The deck should be moved in a harmonic oscillation (heaving or pitching) at a specific...
View ArticleNolinear solver did not converge. Out of memory during LU factorization
Hello, I am building a model using version 4.1, in which heat transfer driven melting of paraffin. Each time I compute, is solves at first and then the following error appears: Nonlinear solver did not...
View Articleadding wavelength to waveguide
Hi please help me,i am new in comsol I want to add wavelength to waveguide. i know the wavelength that i use. but i dont know in which field i enter the wavelength. Thanks
View Articletemperature difference between two points
Dear colleagues, I carried out a study using heat transfer in solids physics. How can I plot a temperature difference versus time between two points (or cut points) into a 1D Plot Group? Thank you in...
View ArticleModeling elastic waves in a solid mechanics study
Hi, I'd like to ask a question concerning the modeling of elastic waves in the structural mechanics module. The geometry is a simple 3D beam, free on all sides. (file attached) My goal is to study the...
View Articlespecifying varing coefficient - interpolation function
Hi all, I would like to specify varing htc via interpolation function and apply it to a heat flux boundary condition. I am attaching a sample file. - Model: 2D-axisymetric (i.e.cylinder, mm), heat...
View ArticleLoading a beam
In structural mechanics module, with Edge load I can Loading a beam with a rectangular load pattern, but I don´t I realize how i´ll loading with another load form like a triangle or another function......
View ArticleTrying to write positive values
I'm working on subsurface vapor intrusion modeling. In solute transport module I need to define a coefficient for vapor sorption which is also a nonlinear function of concentration. The function...
View ArticleHelp with calculation of drag coefficent
Hi! I´m having trouble with the obtention of the drag coefficent for a cylinder immersed in a flow. I´ve been able to read the tutorial of this...
View ArticleProperty: dl error
Hi All, I have a 3D simulation and am trying to plot a streamline, however I keep on getting an the following COMSOL error Property not given - Property: dl Does any one know what this "dl" property is...
View ArticleEvaluating average value of variable along the length
I am solving free and porous media physics in the square domain (3D). I want to calculate average flow velocity through one of the four sides of the wall along the length. In 2D, I know that we can use...
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