Buoyancy in Water
Hi I want to model buoyancy effect of a solid in the water, which solid's density is less than water (hypothetically). How can I model it? Which MODEL should I use ? is any special trick or something?...
View ArticleModeling a Kerr Effect
Hello. I want to model a material with birefringence that depends on the electric field inside the medium, similar to the Kerr effect where the index depends on the square of the field. This is...
View ArticleDeformed geometry or moving mesh
Hello Suppose I have a rectangular object and it expands under some physics (for example, thermal expansion). Which option would capture the expansion (or contraction) in moving mesh physics- deformed...
View ArticleHarmonic Load
Hey, I'm new to COMSOL and I have a few questions about it. I'd like to do a Frequency Response Analysis of a structure with a harmonic load ''shaking'' it with a pre-determined force and frequency ,...
View Article"zero length" element
I am trying to model a bolt connection in an assembly. In order to do so I would like to place a node at the center of where the bolt hole should be (all bolt hole cutouts have been eliminated) and...
View ArticleIncorporating Lagrange Multipliers
Hello again, Thanks to the help of those on the forum I was able to incorporate weak constraints to get accurate flux calculations in my diffusion models. However, I am trying to understand how exactly...
View Articlearea changes when going from 2D to 3D
When drawing a circle the are changes when going from 2D to 3D in a 2D drawing or in a plane a circle is drawn with radius (57,61/2)[mm] resulting in a surface of 0.002602m² when extruding this plane...
View Articlemodeling of airlift reactor
Hi everyone, I have building a model to simulate airlift reactor for vaccine production. I had following the "modeling of airlift reactor" in model library COMSOL but I can't input mass balance to get...
View ArticleCOMSOL APPCRASH and closed
hi I have a problem for the new server computer using COMSOL 4.3 First of all, the performance of server computer is below. OS: windows 2008 server RAM: 512GB CPU: AMD 6238 (x4) GPU: Geforce GTX 550 Ti...
View ArticlePML Coordinate Stretching
When I see the equation mode, PML in one of the direction (mapped coordinate e.g. y direction) is stretched to complex number but another remains only real for my 2D analysis, why is that? Also does...
View ArticleMass in not conserved even in conservative form, multiphase flow of water...
Hello everybody, I have previously posted on a problem I was trying to simulate about multiphase flows (Multiphase Flow LS - Air Bubble in Water Cylinder - Conservative forms fails) and I have tried...
View ArticleObjective Function Gradient Components in Optimization Module
Hi, I'm using the Optimization Module with V4.2a to run a parameter estimation on a time dependent model. The error output for the Levenberg-Marquardt algorithm doesn't reflect the convergence of the...
View ArticlePossibility to import a 2D CAD file to COMSOL?
Hello, I am running the last version of COMSOL (4.3b). I tried to import a 2D CAD file to COMSOL but was not successful! Generally, is it possible to import a 2D CAD file to COMSOL or only 3D files? If...
View ArticleHeat source: Temperature profile instead of heat
Hi, I want to use measured values to define a heat source in the "Conjugate Heat Transfer". I could already generate a 3D-function of these values which can be used as Q. But my problem is that the...
View ArticleHeat Generation in a Disc Brake
This is a basic related to the "Heat Generation in a Disc Brake" tutorial model. my question is how to add a layer of grease between the disk and the pad. same for the "Heat Conduction in a Cylinder"...
View ArticleRegarding beam module in structural mechanics module.
Hi all, Do anyone of you how to add beam module to structural mechanics module.Please help Thanks
View ArticleIntroduce material with the loss or gain in Transient model comsol 4.2
Hi, I am working at transient model for optical application(wavelength = 1.55um) with loss or gain material and also nonlinear material. I know that I can put loss/gain into my material by introducing...
View ArticleMoving Mesh ALE - Applied to unconfined groundwater flow with unknown water...
Hi, I am trying to set up a model that was presented in the paper presented at the 2012 Conference in Milan: Simulation of Pumping Induced Groundwater Flow in Unconfined Aquifer Using Arbitrary...
View ArticleGeometry variation within Time-Dependent solving.
Hello, I was wondering if it's possible to change geometry according to time ( via internal or external function(MatLab)) ? ie: Making a block depth function of time.
View ArticleInterpolation Function Help
Good Morning, I'm having trouble using COMSOL's interpolation function, and I was hoping someone might be able to help. I'm trying to load data from a tab-delimited text file. I've followed the...
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