How Can A Temperature Dependent Variable Changes Permanently?
Hello, I'm using COMSOL 4.3b for simulating a laser-material interaction, and I have predefined several parameters for specifying material's physical properties such as material's density, material's...
View ArticleHow to delete unwanted stored solutions?
Hello, I am simulating large 3D RF problem in time domain in version3.5a. And I found my whole stored file is as large as 40GB, since I stored around 600 time steps. And I want to delete the last 100...
View ArticleAC/DC rmm module - bug report
In the 2D generator tutorial, I changed the prescribed rotational velocity from 'rpm' to 'rpm*tri1(t[1/s])'. tri is a triangle function. Therefore the rotation speed should first increase, then...
View Articlejava.lang.ClassCastException when using LiveLink from MATLAB
Hi there, I've been successfully using COMSOL and LiveLink for a few months now for generating and simulating electromagnetic models. However, yesterday I ran the same MATLAB code as I always do, but...
View ArticleCan cut line result be used in simulation?
I am currently using comsol to simulate a concentration lets name it C on a 2D symmetry rectangle. at one point I need to take a boundary value of C, I am wondering if there is anyway I can take the...
View ArticleHelp me! Error"Internal error in boundary respecting."
Hi, all I want fix it, It is coordinate (-2,06378, 1,35209, 2,8034) Thank a lot Vinh Nguyen
View ArticleError after 300 iteration steps
HI, I am very new to COMSOL multiphysics. I am using CFD> non-isothermal to simulation the room temperature. After 300 iteration steps, I received the error mas at attched. I shall be very thankful...
View ArticleMaximum values over time in a 2D spatial domain
I am running transient simulations of solute transport in a 2D domain. I would like to find a 2D spatial profile of maximum value of solute concentration over simulation time, which may not occur at...
View ArticleRF Module Mode Analysis Study for 3D Metal Cylinder Waveguide
Hello Forum, Thanks in advance for reading and potentially responding with thoughts. I am trying to model a cylindrical metal waveguide, and in particular, I want to solve for the mode shapes. This is...
View Articleout of memory during assembly
Hi All, I am running a heat transfer with radiation, and the error message says "out of memory during assembly". Rigth now, I am using a workstation with 48GB memory. I check the element number, and it...
View ArticleDarcy Law using PDE
Hi, I'm trying to implement the Continuity Equation with Darcy law and the Energy equation using a PDE (base package). The Darcy equation in the continuity is u=-(k/mu)*d(p,x) where k is the...
View ArticleHow to model the water capillary inside fiber and diffusion of water through...
Hello Assume we have a vertical fiber in micro size and very bottom of it is in a droplet. We expect that water is wicked inside and outside the fiber; and at the same time water diffuses from inside...
View ArticleUsing Level Set Two Phase Flow (tpf) for any Solid Material Module
I want to model a two phase flow system where the phases will be Fluid and Viscoelastic (or any other Solid material) and also want to tack the interface using Level Set Two phase flow module. can any...
View ArticleFunction for total spring constant in thin elastic layer
Hello, i'm a relatively new user with comsol, specially with the solid mechanics module. The goal in my work is to simulate the interaction between epoxy and fiber glass. I started with a 2D-model...
View ArticleEvaluate expression for different (specific) solutions
Hi all. Does anybody know how to evaluate expression for different solutions at the same time? I mean something like coupling integral between several modes. For example I have an eigenvalue problem...
View ArticleSurface reaction - diffusion: Robin condition
Hello, I am working on implementing a reaction-diffusion model. I have a particle in solution, where a reaction is occurring at the surface. I want to implement a Robin condition in the boundary of the...
View ArticleB-H curve of nonlinear material and constitutive relation
question1: In the calculation of magnetic field , I have a expression of B-H curve, is B=B(H). Then in the "Ampere's Law", When constitutive relation is "B=mu0*(H+M)", what shoud be filled in the...
View ArticleHow to deal with meshing for the thin bodies
Hi All, I am dealing with some very thin bodies, let's say, the thickness is 2mm, and width is 1000mm. I encounter difficulity to mesh these thin bodies. Do anyone have some suggestions? Thanks.
View ArticleSimulate an on-chip inductor
Hi :) I am new with Comsol and I am trying to draw an on chip inductor (the square shaped one) and then I want to study the electromagnetic effects and the properties (L and Q..) How can I draw the...
View ArticleHow can I find eigenmodes propagating in given direction?
Hi! I have a general question about eigenmode problem in RF module. How can i find only eigenmodes propagating in given direction? For example, let's consider an infinite number of parallel cylinders...
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