Error - Failed to evaluate variable jacobian
Hello, I am currently working with the batteries and fuel cells module and I am attempting to create a model of a micro-scale PEM fuel cell. Right now I am starting by just trying to solve a free and...
View ArticleCoupling Surface Charge Density from Electrostatics to Electrical Circuit
Hi, I have made a model of a varying overlap capacitor with an electric potential on one side as an electret. It seems to work with just ES and ALE but once I add in CIR and set the top electrodes as...
View ArticleConvergence problem in RF module
I am doing some plasmonics simulation using silver nano particles in comsol. For silver particle convergence is either very very slow or there is no convergence in most cases for some specific...
View Articlequestions on point source phase
Hi all, I am trying to simulate the interference of two point sources. I want them to be out-of-phase. In Helmholtz equation model, the two sources are given as weak contribution. One of them is...
View ArticleMeaning of "node" vs. "vertex" vs. "degree of freedom" for linear finite...
Hi there, can anybody tell me what COMSOL means by the word "node" in contrast to "vertex" or "degree of freedom" when it comes to the discretization? I have...
View ArticleFixed time steps
While simulating our case, we have used strict time step with maximum as 1800 seconds. But still, it is taking a time step of 0.1 sometimes. This is making our simulation quite slow during the middle...
View ArticleThermal Stress Evaluation without Solving Heat Transfer Physics
I am trying to generate Thermal Stress about the domain of a spherical body with a coupled 'Solid Mechanics' and 'Heat Transfer in Solids' physics. Instead of actually solving the heat transfer...
View Articlethe free vibration of the cantilever
Hi everyone: The initial displacement D=1.05mm, is placed on the end of the cantilever beam, to solve the velocity response of the beam end. First, I select space dimension 2D, and add physics Beam,...
View ArticlePlot of a line between two points in 3D
Hello, I need to plot a line that describe the electric field between two points in 3D. I tried the way I used to try in 2 D but obviously it didn't work as I wanted. It didn't give me the plot I...
View ArticleSettings for simulating static or rf field between metallic contacts
Hi, I'm a new Comsol user and I'm interested to simulate the 2d field between two electrodes on a substrate. The electrodes can work at low but also at high frequencies. I've been able to draw the...
View ArticleSimple Contact Mechanics Problem
Hi All, I have been struggling a little with trying to implement a contact mechanics. I am modelling indentation of a hybrid polymer base layer in 2D. The polymer base layer is a combination of two...
View ArticleIssues with Full Coupling of Physics
Good day, I am having issues with fully coupling two physics. My system contains the solid mechanics physics coupled with a general form PDE to model concentration change and the diffusive properties...
View Articlewhich kind of solver?
Hi all, i am doing some kind of simulation in RF using 4.3 version comsol and the RAM of my computer is about 30G , how to select the best solver to use almost of my RAM to finish the task as faster as...
View ArticleAsynchronous Machine time dependent startup, singularity error
Hello, I am trying to simulate a ASM in the rotating machines physics, time dependent. The Stator slots are coupled to the electrical circuit physics for a Voltage excitation The rotor slots are also...
View ArticleHow to save deformed geometry so that it can be used as new initial geometry...
Hi. I am looking the ways to save the deformed geometry at the end of analysis, and i would like to use it as a completely new initial geometry for further analysis, by clearing out the previous...
View ArticleStop condition in Electromechanics(emi)
I would like to implement a stop condition similar to what is described for a moving mesh problem. The parametric study would stop when the mesh quality is lower than a certain value, inorder to...
View ArticleHow can I find the flow velocity of a specific coordinate point
Dear all, I would like to ask how can I find the flow velocity of a specific point (x=105, y=2.5) in my channel (it is shown in the picture). In the graph, if I click at any random point I got 3...
View ArticleSessile droplet
I want to put a sessile droplet inside a channel. How to create a droplet of a specific material ? and how do I choose the model ? As a reference I was wondering about the model in one the Paper - A...
View ArticleMeshing and convergence problems
Dear Comsolians, I was finally able to draw the problem in 3D in Comsol :), am also a beginner, lol. The way I have modeled the coils is that they do not form a complete closed loop, thus I assigned...
View Article2 Separate Stranded Coils in Multi-Turn Coil Domain
Hi all, I have 2 separate stranded coils to be modeled for transient behavior (Current Pulse input). Since these coils are not of regular shape (linear or Circular), i had to go with numeric coil type...
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