Boundary condition in laminar flow, Failed to consistent initial value
Hi any body; I have an static flow at initial time on the solid surface. After t=0; I should exert an external force to the fluid bulk so in this situation my fluid has a motion. Here because the down...
View ArticleOpening older files
Hi, I just upgraded my mac OS and the admin installed a newer version of COMSOL (4.4). I was wondering if I still can open my simulations made in older version of COMSOL. I think I had 4.2 or 4.3 .....
View Articledomain labels
Hi all, I would like to ask you, how can I get the label information about the domains in my 3D geometry. the mphgeom() function contains only Edgelabels, Facelabels but not domain labels. I need it,...
View ArticleZooming with mouse wheel
Hello is it possible to zoom on geometries with the mouse wheel? Since this is a standard in all CAD interfaces I know, it would be nice if it was also available in comsol. Thanx Roland
View ArticlePause an ongoing simulation
Hi everyone, maybe this question has been already asked a lot of times, but using the search tool of the forum I didn't find any adequate answer. I need to use my laptop while COMSOL is simulating, but...
View Articlemesh setting
Hello I have a model which is a very thin film with a thickness of um and length of cm. I get convergence error when I simulate it with Heat Transfer module/Joule Heating! I think that I should use...
View ArticleVoltage vs thickness of Piezo
Hi, I am trying to see the variation of voltage generated by a free piezo with varying thickness of piezo, under given strain. I expect the variation to be linearly proportional, I am attaching the...
View ArticleModeling elastic waves in a solid mechanics study
Hi, I'd like to ask a question concerning the modeling of elastic waves in the structural mechanics module. The geometry is a simple 3D beam, free on all sides. (file attached) My goal is to study the...
View ArticleParameter Sweep on Geometry
Hi everyone, I created a geometry whose dimensions are related to a few parameters which I have been defining under "Global Definitions > Parameters". Now I would like to change some of these...
View ArticleRunning two GUI's to utilize remaining memory
COMSOL Community: I currently have a frequency-swept simulation running that comprises 30GB physical /41GB virtual memory, off of an 8-core, 128GB system. Even though a sweep in off-normal incidence...
View Articlefluid solid interaction for blood flow
Hi, I am trying to model blood flow in a cylindrical elastic blood vessel. I am using velocity inlet and pressure outlet boundary conditions. The program does not converge. According to my search, i...
View ArticleAnalytical definition of electromagentic field
Dear all, does somebody know how to define an electromagnetic field in RF/Waveoptics (comsol v.4.3a) module ANALYTICALLY using solution of Fresnel equations, not using ports? For air-glass interface...
View ArticleCan't integrate normal current density nJ over internal boundary
Something I can't understand. See the attached trivial model. In Surface Integration 1, if I select ec.nJ from the menu, I get an error message (same with trying to plot it or export it), but if I look...
View Articlehow to mesh- comsol4.3 version
Hello everyone, I need to know how do mesh the particular cross section in a 3-D Element like cylinder.Hereby i enclosed the image file for the brief understanding this problem. Please let me know how...
View Articleconfinement loss and dispersion curve in pcf fibers
hello, please i need your help to calculate the confinement losses in the fiber pcf, and how to calculate the dispersion curve
View ArticlePDE in weak form
Hello everyone, I have a problem for this equation imposed in weak form in Comsol. someone would have any idea. thank you very much cf: .png
View ArticleCFD in Expanding/Shrinking Domain
I am trying to mimic the displacement of a fluid in a pipe by another fluid. I say mimic, rather than model, because characterizing the interface is irrelevant to the larger goal of my project. So my...
View ArticleAdd physics
Hi, Can some one let me know how to add a new physics to an existing model?
View Articledefining temperature of inlet fluid?
Hi How do I inject a fluid with a required temperature through an inlet? Obviously it's temperature needs to be different from the initial fluid in the model . thanks Dave
View Articletransport of diluted species in microchannel
Hi all, I am trying to calculate the concentration profile of two species with different diffusion coefficients in a narrow tube. The physics I'm using is " Transport of diluted species" for the...
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