Floating conductors with fixed potential difference
Hi, I'm trying to model a conductive instrument placed in an electric field (I'm interested in the electric field flux through a few boundaries of the instrument). To model this conductor, I've applied...
View ArticleTime-discrete solver
Using the Weak-Form PDE interface and the time discrete solver, I am trying to implement a pressure-correction scheme for the Stokes Problem. Since this requires three previous solutions (time steps) I...
View Articleheat transfer with solid mechanics problem
I build a model with heat transfer in solids and solid mechanics, heating from the bottom of the model by adding a high temperature. There's a boundary load set on the top side. To simplify the...
View ArticleFinding Photonic Bandgap Curve
Hi, I am trying to model a photonic crystal fiber to exihibit photonic bandgap. But i don't know how to get the PBG curve. Can anyone help me plz? I also want to know how to operate multiple wavelength...
View ArticleSmall time step & slow solving process
Hi I'm building a 2D, time dependent model relating to Solid Mechanics/Heat Transfer in Solids/Coefficient Form PDE. They are coupled by the thermal expansion and swelling of the solid. The creep...
View Articlelog and failure
hi Everyone, i'm simulating a diffusion through a mask and my simulation does not fail (although the convergence keeps going up and down in a strange fashion) BUT i have the NFail in the log rising, it...
View ArticleWhat is "Maximum Element growth rate" and "curvature factor" in the Mesh...
Under "Mesh" node and then under "size" , I see a section named "Element size parameters". Inside it there is this "Maximum Element growth rate" and "curvature factor" that Comsol always automotically...
View ArticleIntegral over a disk in different positions
Hi! I have computed a magnetic field in a region of space and have defined a disk inside that region. I would like to compute the energy in the disk, which involves integrating the magnetic field, for...
View ArticleLong wire simulation
Hello, I'm very new to COMSOL Multiphysics 5.2a I would like to create long (5 m) and thin ( d = 30 micrometers) tungsten wire sagging in the gravitational field, having electric potential 1800 V with...
View Articlemodifyin mesh didn't modify my results
Hi, I have modified my mesh in order to choose the appropriate one for my next simulations, however i have got the same result for extremely fine as for normal mesh. I'm looking for different values of...
View ArticleUnit syntax error, not sure why
This is likely something very obvious but I can't figure it out. I'm trying to define a variable: omega0 = e_const*hbar_const*sqrt(fermienergy/W) fermienergy has units joules and W has units of...
View ArticleCOMSOL Design of Membrane Deformation using FSI
Hello! We are currently doing research that models deformation of a membrane, and we are using COMSOL Microfluidics 5.2a. We want to know the feasibility of our design we present, as well as feedback...
View ArticleEddy current simulation not converging when velocity increases
My simulation simulates an array of magnets moving over an aluminum plate at a fixed height and a given velocity, and while it computes and yields results similar to those of a numerical analysis, it...
View ArticleHow to choose right conditions
Hello, i have been trying do that this couple of months and i cant solve this problem by my own. I dont know , how and which conditions i need to choose to get all worked up. My main topic is to...
View ArticleThe compression simulation, and the material "exploded" during simulation, why?
Hello everyone, I am just using Comsol to simulate the process of compressing PMMA with the indented shape. I followed the similar example from the Comsol examples, and set the PMMA as a viscoelastic...
View ArticleOut of memory during out-of-core LU factorization
Hi I have a CFD model with 1056,2892 degrees of freedom and a server with 128GB memory. I assume this memory size is enough for computing the matrix I have now. But I keep getting a error: Failed to...
View ArticleUndefined value found
Hi, i can solve my semiconductor model with a relatively coarse mesh. However the found solution is not good enough. It shows some differences to a reference (PC1D) semiconductor model. That is why i...
View ArticleParameter estimation
Hello, I want to determine one parameter k1, which is used over the entire domain. However, objective function values should be compared only at a boundary. According to the Optimization user manual, I...
View ArticleDamped Eigen frequency Analysis
Hei, I am working on calculating Q factor from eigenfrequecny analysis using structural mechanics. I know that Q factor= abs(imag)/2*abs(real) but my problem is when I add damping in the form of...
View ArticleAnalysis of mixed convection flows within a square cavity
Hi , I am new to the topic of solving mixed convection problems in COMSOL multiphysics. I want to validate Fig. 8 of the paper(attached). Stream function and temperature contours for uniform bottom...
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