Internal and external natural convection seperation
Hello COMSOL Community, Firstly I would like to say thanks to everyone who so regularly contributes to these forums and breathes life into them; namely Ivar. I have been setting up a relatively complex...
View ArticleWhich Physics should i choose????
Hello Friends, Am trying to observe the increase in diameter of a hole for an applied electric field. Since am absolutely new to comsol Multiphysics i find it difficult to choose the type of physics 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 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 ArticleSound Absorption Coefficient of Materials
Does anyone know how to simulate the "Sound Absorption Coefficient" of materials? I tried to build a waveguide (impedance tube) on top of the materials, but it doesn't work for high frequency.
View ArticleNonlinear electric conductivity
Hi, I'm currently working on electrical transients simulation using AC/DC module. How can I define nonlinear electric conductivity of zinc oxide (ZnO) in subdomain settings? Thank you
View ArticleTransmission spectrum for optical waveguide
Hello, I am currently trying to extract a transmission spectrum from a Si waveguide on top of SiO2 substrate. There are some gold particles on top of the Si (this configuration is taken from an article...
View ArticleExporting data for multiple Cut planes
Hi all, I'm modeling a mixer and I would like to export concentration profiles at different cut-planes along the channel. I can do a single cut plane export with: Defining: Data Sets -> Cut Plane -...
View ArticleCoordinate system and COMSOL solver
Hi This may sound silly but I need to understand the basics. I am bit confused about how COMSOL handles coordinates. I have a circular geometry in 3D, preferably in theory it is usual to use a...
View ArticleMirroring results across a symmetric plane
Hi guys, Just a simple question: How can I mirror the results through a symmetry plane in comsol's post processing? I want to view the results in full domain instead of half of it. Thanks. SMHH
View ArticleRunning a specific Study node using batch
Hi, I would like to run a specific Study node (suppose I have a model with 2 or more Study nodes) using batch commands. Normally I write something like comsol -nn 8 -np 8 batch -inputfile input.mph...
View ArticleHow to include anisotropy in the solid mechanics module
I am working on a model, simulating an anisotropic material that shrinks and warps due to changes in temperature. I wonder how can I include an initial temperature (thermal strain) in the structural...
View ArticleHow to use parameters between different physics?
Hello, my name is Wang Jiujiang from University of Macau. I am using COMSOL to simulate a capacitor, after I simulated using DC voltage, I want to add AC voltage. After I add a physics--circuit and...
View ArticleHow to use simultaneously straight wave and oblique wave radiation in COMSOL...
Hi everyone! I am using COMSOL to simulate the acoustic lens system. I am experiencing problems in the use of simultaneous straight waves and oblique waves radiation on the same plane in Acoustics...
View ArticleCan not open model made in versions before COMSOL 3.5a in 4.3
How can I open a COMSOL model made in versions prior to 3.5a in COMSOL 4.3? Would someone be able to convert it for me some how? Thanks
View ArticleMicroring resontor Transmission spectrum simulation
Would anybody like to correct my model? i cannot get the right transmission spectrum. Thank you.
View ArticleHow to calculate the otpical waveguide transmission spectrum
How to calculate the otpical waveguide transmission spectrum? I use abs(S21)^2 to evaluate it, but it seems unphysical. Anybody give help? thanks.
View ArticleHeat transfer in a press
Hello, We want to see the heat transfer in a piece of steel. The press is made of a cold and a hot side, with between the two matrix a piece of mica to isolate those two matrix. First we have to...
View ArticleWear Model - Solving a contact problem with irregular geometry
Dear COMSOL, I wonder if you could help me in solving this contact model in COMSOL 4.3. I am implementing wear by solving a quasistatic contact model using the Structural Mechanics module, extracting...
View ArticleMatrix has zero on diagonal
Hi experts, I mat a problem when simulate a AC/DC model. it came out as below: Failed to find a solution for the initial parameter. Segregated group1 Matrix has zero on diagonal. Returned solution is...
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