Eigenfrequency and Temperature in a Cantilever
Hello, I'm using COMSOL for some months. I'm simulating the eigenfrequency of a clamped-free beam (cantilever MEMS). The value of the eigenfrequency at room temperautre is correct (about 6.4MHz) but...
View Articlephotothermal or laser heating simulation in Comsol
Hi, I am new to Comsol. I am trying to simulate the temperature rising of the plasmonic structure during the laser illumination. Assuming the Electromagnetic wave plus the heat transfer will do the...
View Articledefining a Gaussian heat source
hello, I am trying to simulate an hybrid laser welding model using COMSOl.. I need to use a 2D Gaussian heat source but I don't know how to define it or the expression to use.. could you help me? thanks
View ArticleSimple heat exchanger model error
Hi everyone, I'm working on a heat transfer problem and could use some help. It concerns a large horizontal pipe containing an elongated u-shaped pipe (the 'loop'). The pipe contains air and the loop...
View ArticleUnable to evaluate an expression
Excuse me, I am getting an error as Attempt to evaluate real square root of negative number. Function: sqrt Failed to evaluate expression. Expression:...
View ArticleCalculate surface area in which a specified temperature limit is exceeded
Hi, I have calculated the time-dependent joule-heating of a structure, now I like to calculate the surface area in which a specified temperature limit is exceeded for each time step. Is there any...
View ArticleHow to give temperature dependent gas properties?
I would like to solve a multiphysics problem involving navier stokes, heat equation and magnetic field (actually a TIG welding problem ). I have some graphics involving the viscosity, density of the...
View ArticleElement killing during laser melting
Dear friends I am working on laser cutting with moving heat source with subsequent stress analysis. I have successfully simulated the thermal analysis . However, I dont know how to delete/kill those...
View Articleconvergence issues in cojugate heat transfer problem
Hi, I am trying to solve a conjugate fluid flow and heat transfer problem. The problem has a channel with fluid flowing through it and surrounding media which has some heat sources. I am having issues...
View ArticleHow to solve the problem"Attempt to evaluate non-integral power of negative...
Hello, I am solving a Drift diffusion model for plasma using general form PDE. However, I am facing the following error, Failed to find consistent initial values. Attempt to evaluate non-integral power...
View ArticleIncident intensity boundary condition (Radiation in participating media).
Hi all, I am having troubles in setting the correct value of the incident intensity in a "radiation in participating media" problem using a 3D geometry. When I set a precise value of the incident...
View ArticleAccess values of one model in the other
Dear all, is it possible in post-processing, to access all the models that are stored in a .mph comsol file? I have a file that contains two models (with exactly the same geometry) and would like to...
View ArticleAdding thermal expansion
Hi, I would like to add some simple thermal epansion to my model, however I do not have the thermal expansion part of the solid mechanics module... Is there a way to add it via the mathematics module?...
View ArticleConvective heat transfer coefficient
Hi everyone, I'm a beginner in Comsol and I have a very simple problem I can't find a solution for. Basically my model is in 2D and is very easy: I have an horizontal plate from which is flowing a heat...
View ArticlePML refractive index
Hi, I am studying a model of Step index fiber and I want to put a cylindrical PML around the core. What should be the refractive index of the PML , should be same as refractive index of the cladding or...
View ArticleCOMSOL Gold Nanoparticle Electromagnetic Wave
Hi, I'm a student at Pennsylvania State University and I'm trying to make a model for educational purposes. I am trying to create a model that shows that a gold nanoparticle can cause ablation of tumor...
View ArticleNusselt Number Calculation
I am trying to calculate the average Nusselt # over a flat plate vs. Reynolds #. Thus I need to take the average of the derivative of temperature in the y direction at the plate for the various...
View ArticleThermocouple model
I am trying to model the effect of two metals that are in contact with a heat source at one end and isolated from each other at the other end. It should be similar to the Seebeck effect in...
View Articlewhat is emetric2?
hi: I am having trouble understanding a variable in CFD model. The cell Reynolds number is defined as: spf.cellRe= 0.25*spf.rho*sqrt(emetric(u,v)/emetric2)/spf.mu I realize spf.rho is sure the density...
View ArticleExport comsol file( mph) to GDS FILE
Hi Does anyone have idea on how to export (geometry) mph file (Comsol) to GDS file. Need your help please. thanks
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