negative concentrations at flux boundary results in singularity error
greetingsI am working on a heterogenous catalysis model with fast adsorption reactions at one of the boundaries. Right near the boundary at time=0, the concentration of the species being adsorbed is...
View ArticleFluid Structure Interaction
HelloI am trying to model a liquid being injected between 2 thin layers. I am unable to get the liquid to deform the 2 layers and push through to disperse, however.I am currently getting the error :...
View ArticleAcousto-optic coupling
paper name : Time-reversal symmetry breaking with acoustic pumping of nanophotonic circuits.I am trying to simulate this kind of acousto-optic coupling in optical structures. To be simple, say a si...
View ArticleFailed to create boundary layer mesh for domains.
Hello I am doing the 3D simulation of the flow of a gas (air) flowing through a pipe. The Reynolds number turns out to be 3600 depending on the inlet geometry and flow conditions. This implies a...
View Articleshear gradient lift force
In inertial micro-fluidics field, there are many types lift force. Among them, there are Saffman lift force and shear gradient lift force. I think that Saffman lift force and shear gradient lift force...
View ArticleHelp me to solve this error
Failed to find a solution. Singular matrix.There are 5896 void equations (empty rows in matrix) for the variable comp1.Az. at coordinates: (0.0541453,0.02559), (0.054005,0.0258867),...
View ArticleSolar radiation modeling for transparent surfaces
I'm trying to model solar radiation exposure and heat transfer in a window system. I have tried surface to surface radiation, but not sure if this is the correct approach consdering the transparency of...
View ArticleStress on Silicon Wafer
I have a model of a silicon wafer with a labyrinth to thermally isolate the center from a section of the outside. I am wanting to know how strong the wafer will be. I initially set up a 3d model by...
View ArticleEstimation and control of the volume change with integration
Hi everyone. I am trying to calculate the volume of a sphere. I used Integration in Definition > nonlocal coupling>integration. Then, in derived values I try both Volume intergration and Surface...
View ArticleA moving permanent magnet in air
Hi all,I have a 2D axissymmetric model in which I have a cylindrical permanent magnet in air. I have solved the magnetic fields (no currents) for the magnet (step 1, stationary solver) and after...
View Articletemp files with COMSOL
Hi,I am accesing the Comsol using CMC cloud platform. So I have limit for the data storage .When I start my simulation it cause the piling up of huge temp files and I am unable to complete my...
View ArticleSIMULATING HEART BEST
I am trying to simulate chest expansion and fall (normal chest movement when breathing) and how it affects a poezoelectric flat square sensor when placed on the chest. I do not know what study to use...
View ArticleHelp me to solve this error
Feature: Stationary Solver 1 (sol1/s1) Failed to find a solution. Singular matrix.There are 69 void equations (empty rows in matrix) for the variable comp1.Az. at coordinates: (0.019469,0.056542),...
View ArticleProblem while modelling an optical black hole
Hello, I have a problem with this error. I don't know what to do.Division by zero. - Function: / Failed to evaluate variable. - Variable: comp1.ewfd.kinp - Defined as:...
View ArticleContent is not allowed in prolog
Hello Comsolers!I foolishly ran an very long simulation and got an Out of Memory error. I edited the comsol.ini file as in the support below. https://www.comsol.com/support/knowledgebase/1243When I try...
View ArticleDisagreement between total heat flux and lagrange multiplier
Hi all,I am modeling a two-phase Stefan problem (melting) and come to notice that the total flux across the phase transition boundary is different both in magnitude and, at somee point, opposite in...
View Article3D Optical Microring Resonator
Hi admin, would you suggest to me anything (blog post or webinar) regarding the 3D design of Optical Microring Resonator ?
View ArticleResidence time
Hello, anyone knows how to generate residence time distribution graph in comsol ???I set up final time= 2 seconds and 5000 particles. I defined Wall condition as dissapear at outlet: This graph seems...
View ArticleSetting in heat source
In two-dimensional plane, how to set up the heat source to make simple harmonic vibration in the center of a plane？
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