Principal stress 2d vs 3d
Hi everyone, I have the same model made in 2d and 3d. First and second pricipal stresses are similiar in both models. But third principal stress in 2d are unrealistically high, however in 3d have value...
View ArticleExtracting absorbed power
Hi all! I am currently doing a 2D model where I have an incoming power, and then I have absorption within the material. As a result, I have the value of the intensity everywhere, but I don't know how...
View Articlehi
can anyone explain to me what is geometry linearity and non linearity? what is the different between them? i'm not clear about that... thank you for advanced... :)
View Articlesolving helmholtz equation
I wish to solve Helmholtz equation for an Axi-symmetric geometry. The problem geometry consists of a excitation source a tube and air box (all rectangles). Is it possible in equation based modeling?....
View ArticleTransient Hot Wire Method
Hi Everyone! I'm new on COMSOL so I don't know too much yet. I need to simulate the transient hot wire method, I don't know how to start with, and I cannot find any example. Could somebody help me with...
View ArticleRegular Meshing
Hi all, I've been asked to create a regular mapped mesh for a cube which has faces of 10 by 10 square areas throughout the whole of the cube. I'm applying a magnetic field to the cube and I wanted to...
View ArticleHow is the penalty factor used in the penalty method?
I am modeling a transient contact problem using the penalty method instead of the augmented Lagrangian method. How does COMSOL use the penalty factor when the penalty method is being used? I understand...
View ArticleMagnetic field
Does anybody know how to write this expression on comsol ( ∇/B/^2 )? I meant expression that replace "the gradient of the magnetic field norm square". Thank you
View ArticleFailed to evaluate variable jacobian - using a step function
Hi every one, Im trying to put a BC (volumetric flow rate) in my model as a step function. But the following error occur: Failed to evaluate variable Jacobian. - Variable: step1 - Geometry: 1 - Point:...
View ArticleMax value of a field and its coordinates
Hello, I know that there have been a lot of posts about this topic and I have read many of them but I am still as dumb as before. I need to find the value of the maximum value of the field in a domain...
View ArticleUse contour plots as geometric entities
I saw in the release highlight video that in v4.3a that you can use contour plots as geometric entities. How do you do this?
View Articlestart comsol server on cluster on multiple compute nodes
Dear, I would like to run the comsol server on multiple nodes, with each 8 cores, on a linux cluster. For this I use the following command in a PBS script: comsol -nn 1 -np 8 -f ${PBS_NODEFILE} server...
View Articledialysis
Hi, I have got the attached model on dialysis process at COMSOL site. I have some questions regarding the solver. As you can see, under the "Stationary Solver 1" there are two nodes- Fully Coupled and...
View ArticlePlot of Temperatures for a Time Dependent Step
Hi, I was running a case last week that included several physics, including heat transfer. Just by chance, I looked at the computed temperatures at the end of a steady state step and again at the start...
View ArticleVariable modifications between solution iterations
I'm developing a transient model using the Livelink interface. The model first calculates an initial solution for the first time window, then I would like to modify the state variable values due to...
View ArticleProblem: Oil Droplets Seem To Dissolve In Water (Two-Phase Flow, Level Set)
I have a problem with my "Two-Phase Flow, Level Set" simulation in COMSOL 4.2. I am trying to simulate the formation of oil droplets in water by hydrodynamic flow focusing. The water and oil are...
View ArticleCOMSOL Releases COMSOL Multiphysics version 4.3a
We at COMSOL are proud to introduce version 4.3a of COMSOL Multiphysics to the COMSOL community See: www.comsol.com/products/4.3a/ This introduces: * LiveLink™ for Excel® * LiveLink™ for Solid Edge® *...
View Articlebuilding piezo ring projector (electroacoustic transducer)
Hello, I plan to build piezo ring projector, but I don't decide to build it as 2d axis symmetry or entire 3d model. My electrodes would be located circumferentially. 2d model would be problem because...
View Articlehow create solids
Hi, I imported two objects as .stl files: the topographic surface-imp1 (see figure topo.png) and the top of a geological unit-imp2 (see figure top.png). Finally, I added a block-blk1 (see figure...
View Articleoxygen dc discharge
Hi I have simulated oxygen dc glow discharge for a month,but not success. I use the model of positive_column_2d in the model library and change Ar to oxygen.The reactino and date come from...
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