Singularity Error
Hi.Repeated error test failures. May have reached a singularity. Time : 35489.13564466919 Last time step is not converged.How can this problem be solved?
View ArticleDifferent solvers and their influence on the obtained results
Hello!I'm currently using COMSOL for a 3D microfluidics problem and I am performing a mesh refinement study. As I am quite new on the subject, I am only using different element sizes for a default...
View ArticleUndefined variable , Failed to evaluate Jacobian of expression
Feature: Stationary Solver 1 (sol1/s1) Undefined variable.Variable: comp1.wGeometry: geom1Domain: 0 Failed to evaluate Jacobian of expression.Expression: comp1.w Failed to evaluate Jacobian of...
View ArticleQuestion about Geometrical Optics
Hi all,I'm new to COMSOL MultyPhysics, and I'm writing this email to ask you some questions about my Geometrical Optics simulation.Please refer to the mph file I've attached.When I try to use help...
View ArticleSimulating X-ray
Hi all, I am new to comsol. Is it possible to simulate X-ray using COMSOL Multiphysics.Thanks.
View Article"Undefined" variable won't allow my study to execute
Hi all,First off this this is my first real project in comsol. It was handed to me to fix, and I've gotten it this far. Now my defined variable shows up as undefined, causing the entire program to...
View ArticleNon-Newtonian Laminar Flow, user defined flow law
I am trying to model ice (non-Newtonian laminar) flow under martian conditions using a flow law used in the literature for non-terrestrial ice modeling. It is essentially a power law form but combining...
View Articlevariable names
I would like to define functions for some material properties and need to use variables like shear rate in the function. I found from other posts that, for example, the laminar flow shear rate is...
View Articlegeneral stress-strain relation for fluid
Is it possible to define a general stress-strain relation for non-Newtonian laminar flow? Laminar flow seems to require you to define a dynamic viscosity. However I am trying to implement a flow law...
View ArticleAbout langmiur probe in comsol
Hello,everyone! I have a question in my thesis topic.I wonder if the Langmuir probe can work in the established comsol model, and if so, is it possible to define the probe portion directly in the...
View ArticleExplanation for the irregularity in my model
Hello, I made a 2D model for a single slit diffraction using EM waves and frequency domain. There seems to be some irregularity in the planar wave before the slit. Is this due to some reflection that I...
View ArticleSimulating a half filled eppendorf tube in a centrifuge
Dear all,We try to model the flows in an eppendorf tube while it's rotating in a centrifuge (positioned under an angle).We where succesfull in simulating a fully filled tube using the rotating...
View ArticleChange the label of reference system
Hi, is it possible to change the default label of the reference system {x, y, z} in a different triplet named {1, 2, 3}? It is just a matter of graphics especially when exporting an image of the model....
View ArticleAdditive Manufacturing model - requesting feedback
Hello fellow Comsol users,I am currently working on a layer-by-layer thermal simulation for additive manufacturing and by now, my results are not bad, though still far from perfect. In order to further...
View Articlesolid.pw
Hi all,I have some doubts regarding the variable solid.pw ; In particular, which is its meaning and which is the difference between solid.pw and solid.pm?Thanks a lot, Maria
View Article2DEG IN COMSOL
If anyone could share their insight on acheiving the 2DEG in a HEMT in COMSOL, I would be grateful.
View ArticleHow to apply comsol moving mesh in weak form pdes application mode?
Hi,I am simulating a bubble moving in fluid using Weak form PDEs application mode. I am applying moving mesh capability. The problem is, my mesh moves but the bubble do not move. Please can someone...
View ArticleMobility analysis in electron beam interaction
Hi everyone, I am trying to simulate a model to calculate the mobility of the charge carriers in a semiconductor on which some potential is applied and it interacts with a beam of incoming electrons...
View ArticleClik here to view.
How to set the Values of dependent variables
I want to solve a pair of equations which are based on other two study steps, but in the setting of the "values of variables not solved for", I can only choose on study( and i actuallly want to add two...
View ArticleUse interior fan to resemble submersible mixer
I am trying to make a 2D model of a reservoir filled with liquid, with submersible mixers in it. In 2D, the only option I see is to use the interior fan, but I am uncertain what values I should use as...
View Article