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 ArticleConvergence Problem: Error smaller than Tolerance
Hi everyone! I am trying to model non-isothermal, reactive fluid flow in a channel with catalyst-coated walls. Therefor I couple the "Transport of Concentrated Species"-module with the "Non-Isothermal...
View ArticleComsol 4.2a Java error with Mac OS X 10.8.3
Hi every body, I am coming back with my "unexpected error". It seems that it should coming from Java. I am working under Mac OS X 10.8.3 and with Comsol 4.2a It appears an expected error with the log...
View Articletime dependent boundary conditions
hello all.. i am solving a time dependent heat transfer problem.. at the start ,for a rectangular domain boundaries 1 and 2 are insulated and 3 and 4 are assigned with constant temperature.. after some...
View ArticleHow to integrate a table result
Hello, I have calculated surface integrals for total flux over particular features in my geometry. This outputs a table of total flux in (mol/s) vs. time points. I would like to then be able to...
View ArticleWhat is convergence?
I'd just like to know what convergence is - in the context of COMSOL.
View Articlefailed to generate mesh for face
hello, i imported a solid geometry to comsol, but when i generate mesh i get error: failed to generate mesh for face, i tried to make custom mesh for these faces, but did not solve the problem. can...
View ArticleDiaphragm
Hi, I am trying to do simulation of air horn diaphragm, Inputs: Diaphragm dia and thickness and material property. Input pressure on diaphragm. Output: Max deflection of diaphragm. Kindly provide me...
View ArticleSimulation time for 2D and 3D vastly different (with comparable DoF)
Hello, I have a question regarding relative simulation time for 2D and 3D structure. I am using COMSOL RF module to simulate an optical structure. When I try a 2D case with very fine mesh density and...
View ArticleParametric sweep and geometry change
a,b,theta_a and theta_b are global geometry parameters. theta_a = 2/a, and theta_b = 2/b. a,b,theta_a, and theta_b are all used in geometry creation. I am running a parametric sweep for parameters a...
View ArticleDiscrepancy between particle trajectory and streamline?
Hello, I'm trying to teach myself how to use the particle tracing module, so I'm modeling a simple T-junction microfluidic channel. I get an unexpected result, however, when I trace the particles....
View ArticleUsing a derived variable as an input variable for another study
Hi, I have searched through a lot of these threads but I can't seem to find a good answer. I have applied an oscillating body load to a resonating structure (Model 1) and I am able to plot the...
View ArticleIs Cap Face feature is existed in COMSOL 4.00
Hello, I am wondering if someone still uses COMSOL 4.00 and can guid me how to block some holes in my geometry. Is Cap face is existed in COMSOL 4.00 as its in COMSOL 4.3 Many thanks Faisal
View Article160um long Gold rods - excessive reflections.
Hi guys, I'm hoping someone can help me with an issue I'm having in COMSOL. I'm trying to model a 160um by 13um long gold rod in order to get extinction spectra so I can figure out where its peak is...
View ArticlePlot a formula
Hi, I am trying to do simulation of resistivity changing versus deflection of a membrane. the membrane is subject to an input pressure from range 0 to 100[kPa]. I simulate the model parametric and...
View ArticleIn joule heating ,how to compute the resistance of a body?
In joule heating ,how to compute the resistance of a body? can you tell me the formula? such as voltage is V, the symble of current is what and the symble of resistance is what in comsol? Thanks a lot!
View ArticleTime integration in comsol 3.5a
Hi everyone, I am just wondering if there is a time integration function in comsol 3.5a. I am calculating fluid flow rate through a boundary and which is a function of time and I would like to...
View ArticleRadial diffusion
HI, I am trying to build a 1D model which is a line, but I want the diffusion to be radial instead of linear, I know that the equation is : dC/dt = D[ d2C/dr2 + (2/r) * (dC/dr )], but I do not know how...
View ArticlePhysics for a elastomeric vibration isolator.
Good morning. I'm almost finished with my model. The model consists in : 1 - Base. ( Base ) 2 - Elastomeric Rubber. ( Borracha) 3 - Lid. (Tampa) 4 - Screw Hole.( Parafuso ) The Screw Hole receive the...
View ArticleVolume at constant temperature
Dear all, I am using the heat transfer module to simulate heat flow through a rod. The rod is connected to a piece of copper that is held at a constant temperature. The problem is that Comsol only...
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