Acoustic velocity
Hello all, I am looking for a definition of acoustic velocity implemented in Comsol (Pressure acoustic/frequency domain - no flow). I want to make sure that what I am getting is exactly what I need....
View ArticleConvergence issues with level-set conservative form
Hello Everyone, I am trying level-set conservative form for droplet generation in flow focusing device. I have tried the following: (a) non-conservative form: it converges well but mass conservation is...
View ArticleCurrent density and resistance in piezoelectric device
I am trying to simulate the current density in a piezoelectric device. The geometry is a simple rod with a fixed boundary (also ground boundary) and a surface load on the opposite boundary. I can...
View Articlerf mems switch design (comsol 4.2a)
HeLLO, i'm working on designing a switch that should work on rf range. I'm able to draw 2d structure in work plane but still not able to fix one side of the cantilver beam. i hve following questions,...
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 ArticleModelling Surface Plasmon Resonance on Nanorods
Hi. I am trying to model single gold nanorods of different size and shape extruding out of a thin gold layer with visible wavelength light incident upon it. The aim of this is to see how the geometry...
View ArticleSurface Density Charge As Function of Space
Hi, I have the following problem on Comsol 4.2. In my model I want to vary the Surface Charge Density depending on the radial direction r. When I enter it as a function exp(-r) in the "Surface Charge...
View ArticleAnalytic function in Geometry
Hello to everybody. Just a simple question, is there a way in Comsol to create a geometry using an analytic function? It seems to me it's not possible without going throught matlab and importing an...
View ArticleWind turbine tower
Hello everyone, I would like to design a wind turbine tower, along with the blades, in COMSOL 4.3. The parameters are: Height = 87.6m Base dia = 6m Base Steel thickness = 0.035m Top dia =3.87m Top...
View ArticleHow to obtain the density distribution
I’m working with soil plasticity and I want to obtain the density after the compression. Opening the model results the following error message: cannot evaluate expression. I don’t know what I have to...
View ArticleDifference between terminal Boundary condition and Electric potential...
Hi, I am modelling a free PZT patch. I have to apply a voltage potential of 20V across the top and bottom of the PZT patch. (attaching the model) I am doing it via two methods, (a) applying "electric...
View ArticleCoupling Stationary study -> Time dependent does not work
Dear all, I have a very simple model (attached): a 2D model where I impose an initial strain, that generates stress. This stress will be relaxed by creep. The stress caused by imposed strain is...
View ArticleDerivative of a dependent variable
Hello, I am using the values of a dependent variable 'phi' and its derivative in Matlab. For some reason, the numbers of nodes are different between the original dependent variable and its derivative....
View ArticleRing of varying width
Hello, I'm trying to build a ring that has a nominal radius but whose width (thickness) varies as a function of the angle phi around the ring. I've created a cylindrical coordinate system but can't...
View ArticleRing of varying width
Hello, I'm trying to build a ring that has a nominal radius but whose width (thickness) varies as a function of the angle phi around the ring. I've created a cylindrical coordinate system but can't...
View ArticleHow to export high quality images when exporting images sequence
Hello Everyone, I am using COMSOL 4.3b and I do know it is possible to acquire images with somewhat higher quality using the "Snap shot" button but that only takes one image. I am wondering if it is...
View ArticleHow to deal with Contact problems, Adhesion!!
Hello Everyone, I am dealing with the topics of contact mechanics and adhesion. In my case, two surfaces are adhered strongly and I would like to model the detachment of contact or treat it as a crack...
View ArticleTime dependent adaptive mesh refinement output is on every mesh refinement ->...
Hi, I am evaluating the use of Comsol Plasma Module for the simulation of streamer propagation. The nature of the problem requires the use of adaptive mesh refinement in time. It seems that Comsol...
View ArticleSolving multiple modules simultaneously.
As the subject states, I am trying to solve two modules simultaneously. The model is of two electrodes with a solution above them. One module is a partial differential equation in place of...
View Article