parameters
Hi everyone, I have a simple question for you. If I have a variable 'D' , coeficient difusion, depends to temperature (T) with the expression D(T)=0.29*T. the range of temperature is (900 kelvin to...
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 Articleoptical Waveguide
Hi I am defining 2D waveguide from Er:Ta2o5 waveguide in top and bottom of sio2 substrate, now i want to define electromagnetic wave to this.and then i want to calculate the gain. 1-how can i excite...
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...
View ArticleHelp...Which Iterative solver settings for 3D RF module with periodic...
Hi All, Can somebody help me with my solver settings confusion. I'm trying to setup a 3D RF module simulation with around 250.000 elements only with periodic boundary condition. I read that I should...
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 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 ArticleERROR: nonlinear solver did not converge, when simulating ball movement in...
Hi all, I have seen several threads about this error and tried to figure it out myself using the sample cases but I still fail to simulate this. Any help will be greatly appreciated. I am trying to...
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 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...
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