modeling of Diffusion
Hi, I want to model a simple mass diffusion process, but with a concentration dependent diffusion coefficient. In variable I defined a function for diffusion coefficient. but when I want to solve the...
View ArticleMeshing problem for coaxial cable with helical inner conductor
Hi Good day. I am using a coaxial geometry which has helical inner conductor and cylindrical outer conductor. I am also using emw physics.while simulating/mesh generating I am getting error which...
View Articlevertical exaggeration
Hi all, I'm trying to change the views of my 2D plot in order to have a vertical exaggeration (1:4). I've tried to play with the lock aspect ratio but it seems the model is squeezed into a cube-like...
View ArticlePrescribe number of Meshing Elements
Good day, for a model of simple geometry (sphere) and fixed volume, is there a way to define a specific number of meshing elements? I am trying to solve my system with a specific number of elements and...
View Articleelectrohydrodynamic problem
Hi all, I'm currently simulating the electromechanical effects of water droplets under both AC and DC voltages. The water droplet is placed between an energized and grounded electrode on an insulating...
View ArticleGeneration of thicker boundary layer mesh
Hello guys I wanna make some think boundary layer meshes. In my simulation, the boundary layer thickness delta is so big in that Re_x = 9.8 and delta = 5.0x/sqrt(Re_x). So I think the boundary layer...
View ArticlePermanent magnet machine modelling!
I am simulating a permanent magnet generator, in 2D Comsol, 'emqa', 'ALE' mode. But there is a problem concerning magnetic circuit saturation as the followings: - My programs are convergent with linear...
View ArticleHow to find what "compute differential" documentation
When I am plotting a Nyquist plot, I came across this option "Compute differential" under "Expression evaluated for:" option. I just don't know what this means. But instead of asking what it is, I want...
View ArticleError: 'Non Linear Solver did not converge'
Hi, I am working a a 2D model of a rotating machine. I am using the material soft iron (without losses) from the ACDC material library. Every time I use the HB curve as the magnetic field constitutive...
View ArticleMagnetic Force on an armature
Hello I'm dealing with a very simple problem that has been very frustrating for me! I would appreciate if any one can assist me with that. I'm modeling an E-shaped core in 2D magnetic field module. It...
View ArticleLarge Eddy Simulation
hello I want to use Large Eddy Simulation on comsol but I can't found it. Can you help how to do this. thanks a lot
View ArticleBase vector coordinate system
I am modeling the anisotropic behavior of a plate that have fibers oriented in different directions. For this purpose, I am using the structural mechanics feature. I am orienting my fibers using a...
View ArticleInitial negative concentrations
HI All, I am trying to simulate a A+B-->C chemical reaction. I dont know why my reactants (A and B) concentration is going negative. How do I fix this? I have attached my model as well as pic of the...
View ArticleCreep - Plasticity
I want to use the non-linear structural mechanics module for simulation of plastic deformation by yielding. There is a creep module and a plasticity module. In the creep module, I find more suitable...
View Articleimport particle positions in Particle Tracking
Is it possible to import particle positions in COMSOL for particle tracking? If not, can you add one, please?
View Articlehow to do moving mesh in 4.2a
Hello everyone I am implementing a rectangular piezoelectric converter, in which i want to be vary the length and width of the piezo layer via moving mesh ale. I studied one of the paper of "Thickness...
View ArticleCountor data set does not generate plots
Hi, I´m solving a very easy Laplace equation on Comsol, I would like to extract values of some variables I´d define along the isolevels of another user define variable. I´m able to create the Contour...
View ArticleFluid flow with a moving solid object/hole
Hello, I would like to model the airflow in a room occupied with people, and to allow the people (cylinders) to move around in the room. Is this possible in COMSOL? For a silly example in 2D: I have a...
View Articleexport mesh data for an explicit selection
Dear all, I am a relatively new user COMSOL with a lot of Finite Element experience both on the programming and theory level. I started with COMSOL today which went actually quite fine and fast. I...
View Articleoptical fiber modeling
Hi everybody, I'm dealing with a very simple problem that has been very frustrating for me! I would appreciate if any one can assist me with that. I am performing a simulation of light coupling...
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