Waveguide amplitude errors, scattering boundary condition
Hello everyone! I am modeling a waveguide with the purpose of verification, but I am getting high errors in amplitude when the length of the waveguide is not a multiple of the wavelength of the...
View Articleaccuracy in evaluating refractive index
Hi, I am using RF module > perpendicular mode in order to simulate the distribution of modes and get the refractive indices, when I use related m.file of the geometry ,I get refractive indices with...
View ArticleEvaluation of calculated parameters on a specific grid of points
Hi all, I am doing some calculations on solenoid magnets and would like to get the magnetic flux density vectorial components at specific points of a helix that are defined in an external file. I would...
View ArticleOptimal parameters in a GMRES solver with GMG preconditioning
Hi, I am solving a high-frequency 3D acoustic problem with millions of DOFs. Documentation suggests to use a GMRES solver with GMG as a preconditioner. However, it gives very little details on the...
View Articlefailed to evaluate jacobian in using velocity field in fluid particle tracing
Hi, I have tried to edit drag force's equation view in fluid particle tracing(fpt). COMSOL for example, uses "model.input.u1-fpt.vx" for relative velocity in x direction but when i use it in my...
View ArticleFlow between parallel plates
Hey, I am trying to model flow between 2 parallel plates both of which are moving towards each other. The equations applicable are Continuity and Navier Stokes. However, I am quite not able to find the...
View ArticleHeat transfer from the pipe to surroundings
Sir, We found three options for "Wall Heat transfer" in "Non-Isothermal Pipe Flow" namely 1. Temperature (nitf/nitf) 2. Temperature (nipfl/nipfl) 3. Userdefined. (with an option to check "Take average...
View ArticleMeasuring the temperature at a point
Sir, In a non-isothermal pipe flow model, we have specified wall heat transfer with external temperature as 293.15K and the check box for taking average from adjacent domains is also checked. After...
View ArticleHyperelastic Material Models
Are there any talks about COMSOL implementing other hyperelastic models like Yeoh, Ogen or Arruda-Boyce? Thanks.
View Articlerf mems switch
can anybody upload a .mph file of rf mems switch ? i am new to Comsol. and ii want to study a movement of mems switch on this s/w.
View Articleabout heater simulation in the room
Hello! I am use comsol 4.3a , and use the non-isothermal flow physics to simulate the heater in the room. And the room has a door , and I want to set the door is open, and it is connect to the...
View ArticleHow to apply harmonic and random vibration's load?
Hello, I want to know how to apply harmonic and random vibration 's load in comsol v4.2, my previous operation is that first, apply a boundary load, then give a range of frequency, am I right? or...
View ArticleFailed to evaluate variable in particle tracing module
Hello! I'm trying to simulate particle temperature in particle tracing module. But, when I try to plot a line graph of particle temperature, I see this: Failed to evaluate variable Variable - mod1. Tp...
View ArticleScatterer on substrate, RF module
Dear All, Probably some of you RF module users saw module “Scatterer on substrate” in model gallery. I have question about that, and I have question about total field formalism in generally. So, basic...
View ArticleCreating selections based on geometric objects
I've got a complicated geometry full of small spheres with a single layer. I made them by editing a .java exported file from a model that I created with some of the spheres so I could get the basic...
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 ArticleUniform Magnetic field?
Hi everyone, I am wondering how I can generate a uniform magnetic field in Comsol. Basically, I want to simulate a metal particle moving in this uniform field. Now I am thinking put all the particles...
View ArticleMoving items relative to each other
Hello, I am a beginner user, and I was wondering if anyone could help with my problem. I am trying to calculate electrostatic forces between objects, as one is moving relative to another. Must I create...
View ArticleMapped mesh in 3D
Dear all, 1-I trying to mapped mesh a solid in 3D, but it sends me an error message "Error: 7161:The mass matrix is zero" when i try the eigenfrequency, and yet if the default mesh does not send it....
View ArticleError with mesh change
I made a simple eigenfrequency study with a beam using a Free Tetrahedral mesh and it worked fine. But, when I change the mesh type to Mapped and define the size of elements to 5mm, I received an error...
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