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 ArticleUnable to create mesh : Error Free Tetrahedral 1
Hi everybody, I am having this error when I try to mesh a 3D structure : The following features have problems : Features : Free Tetrahedral 1 I don't find a way to have more information about this...
View Articleadvice for simulation set up or suitable tutorial (3D stress distribution...
Hi All, I am trying to help my fellow Orthodontics to showcase COMSOL's ability to simulate one of his problem. But I am struck and getting inconsistent results. The simulation is very basic and...
View ArticleModel couplings: Integration vs. Summation over nodes
Hello, I am working with two modules Structural Mechanics and general form PDE as coupled. I need a model coupling to define an integration. When I choose "Summation over nodes", my model works fine,...
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 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 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 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 Article"Failed to compute elastoplastic strain variables" Help Please
Hello, I am an absolute beginner at COMSOL Multiphysics and I am trying to model the effect of the movement of soil on a steel pipeline buried in it. I have attached the model file with this post. I am...
View Articlehow can I use plasticity model in the poroelasticity module
I want to use soil plasticity model in the poroelasticity module? How can I add soil plasticity model into the poroelasticity module? I notice I can add soil plasticity model in the structural...
View ArticleRichard's Equation questions
Hi, I'm trying to use COMSOL to model water infiltration and evaporation in porous media. Few questions in this issue: 1) How do I define a boundary as open boundary for Evaporation. How do I define...
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 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,...
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