Transport of Diluted Species
Hi, I would like to simulate a problem with transport of diluted species. The simplified problem looks like this: Think of two liquids in a small channel with big infinite reservoirs at the ends....
View ArticleFloquet boundary conditions in multilayer structure.
Hi all, I am trying to simulate a multi junction solar cell (for eg: Si/SiO2/Al) and trying to study the electromagnetic behavior of it. For periodic conditions I had used floquet boundary conditions,...
View ArticleError in DEP simulation-Help
Hi All, I m getting simulation error while simulating DEP based separation.I choose particle tracing with time dependent study, I m able to simulate for laminar-starionary, electric field-stationary.....
View ArticlePiezoelectric transducer
I am going to model langevin piezoelectric transducer in comsol 4.3b.I have following questions in my mind: 1.How to calculate resonance frequency of the whole transducer and resonance frequency of...
View ArticleHow to find partial derivative of dependent variable at one point
I am using diffusion time dependent model with two dependent variables cp and cb. My equation of cb requires me to input "partial derivative of cp at x=0" i,e cb=k*pd(cp,x)|(at x=0) k is constant. And...
View Article2D TRANSIENT Heat Transfer Problem
Hi everyone, I am encountering an error in the time dependent situation - Failed to find consistent initial values, last time steps not converged. I have specified 'initial values' and the required...
View ArticleCritical force to bend a cylinder
Hi, I have a cylinder attached to the top of a block (bottom of the block is the fixed constrain). Uniform load is evenly applied along the entire length of the cylinder, and faces the same direction....
View ArticleMean operator requires an adjacent entity of higher dimension
Hi, I am modelling a 3D DC discharge plasma model, My model is a lil bit complex and i have followed the same steps as a 2D DC discharge plasma model. Everything is built but when I try to compute the...
View Article1D plot: plot height in function off it's width (2D geometry)
Hello, I was wondering if there was a built in function to plot the height of a geometry in function of it's width. I thought this would be specially interesting if it was possible to plot this when...
View ArticleTransient Simulation - Continue option
I have ran my transient simulation from 0 - 900 s with 1 s time step. Now I want to continue the simulation from 900 s - 960 s with 1 s time step. How to do this?
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 ArticleError: Internal error: cannot convert ElemStruct to double
Hi everyone, Since this morning I have this error on my computer for all simulations where I use periodicity boundary conditions: Error: Internal error: cannot convert ElemStruct to double. It involves...
View ArticleUndefined value found
I had great trouble meshing a geometry. After I refined the mesh and was finally able to mesh it, I clicked the compute button. 78 seconds later, I got this message: Undefined value found. - Detail:...
View ArticleUnidirectional coupling of a time dependent study to a stationary study
Hello, I am using structural mechanics module and a stationary study to calculate stresses and strains in a simple 2D axi-symmetrical model. The model has a thermal expansion node. I have another study...
View ArticleEvaluate a path integral
Hi, I need to evaluate a path integral of a known function f(x,y,z). The path p(t) is a solution of an ODE. dp/dt = E(x,y,z) p(0) = p_0 Here, E(x,y,z) is an electric field solved from a previous...
View ArticleAcoustic Band Structure of Metamaterials
Hi folks, I have been trying to find the band structure of an acoustic metamaterial. I have been attempting to adapt the "Bandgap analysis of Photonic Crystal" tutorial given for COMSOL 3.5a to 4.3. I...
View ArticleFrequency Sweep question
Hello, Simulating on AC/DC module. I'm having 3 frequencies: 10kHz, 100kHz and 200kHz in "Derived Values" and I would like to know how to do the frequency sweep? P.S.: Noone able to help out? Best...
View ArticleHow to couple two physics model both are time dependent and affect each other
Hi, I have a problem like this. For a simple description: model 1 (corrosion): F1=(X1,X2,X3, F2, t), for example F1 is corrosion depth, F2 is stress model2 (solid mechanical ): F2=(Y1,Y2,Y3, F1, t)....
View ArticleHelmholtz coil not solved correctly
Hi, I am a beginner in Comsol and I am trying to solve for an anti-helmholtz coil configuration. I followed the instructions given in the help manual but the solution seems to be wrong. Furthermore,...
View ArticleVariable time stepping
Hi Would you help/suggest me on how to set up a variable time stepping scheme in a time dependent solver ( COMSOL 4.2a) Thanking you in advance
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