Model 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 Articleelectromechanics
Hi, Can anybody tell me how to apply vaccum of 70-mtorr around my model clamped-clamped beam resonator.Something like keeping my model inside a chamber of vaccum.
View Articleinitial Values of Variables Solved For
Hi, I have someting to know. As you know, the initial condition set is as follows: initial Values of Variables Solved For Method: initial expression, Solution Solution: Zero, Solver1, Solver2 in...
View ArticleHow to solve a ODE or PDE equation?
Hi~ I try to use COMSOL to solve the mathematical problem. I have a PDE equation in attachment. How could I use COMSOL to solve it? Thank you~
View ArticleImpedance mismatch in quasistatic
Hello everybody! I need the help of people familiar with AC/DC and RF module. I am working with a 3D structure consisting of 2 pads, 100um*200um*0.2um, separated by a 1um slot line. The pad are shorted...
View ArticlePipe flow module / Falied to evluate variable Jacobian
I am working over a simple pipe flow problem, where I encountered with an Jacobial Error saying ; Failed to evaluate variable Jacobian. - Variable: mod1.nipfl.u3 - Geometry: 1 - Boundary: 7 10 13 I...
View ArticleTheory of Brinkman equation
I'm checking the theory of the Brinkman equation in the manual. There's a term I don't understand where stems from: 2/3nu(nabla u). I also checked the given references but this term is not metioned....
View ArticleLivelink for Matlab
Hi, I would like to create a simple model using API in Matlab. When I type the command "shell.feature.create('fc1', 'FixedConstraint') ", errors "Unkonwn feature ID#FixedConstraint" exsit. I have...
View Articlemodel coupling
Dear sir or madam, I have a problem about coupling of a laminar flow domain and thin film flow-shell domain, 3d case. I have to transfer the pressure on an edge to the whole surface,shown in the...
View Articleliquid loading
I'm a beginner level COMSOL user and new to this forum. So please excuse me if I happen to ask a really silly question. I've been trying to simulate the behaviour of a piezoelectric crystal upon...
View ArticleCavitation in thin films
Relating to this topic from 2011: www.comsol.com/community/forums/general/thread/22758 Are there already tools available within Comsol to investigate cavitation effects in thin fluid films (such as...
View ArticleComsol won't create multiple meshes
I have a problem with Comsol and meshes. I have a carbon fibre, with copper at either end, sitting on top of a piece of glass. I illuminate the carbon fibre and look at heat transfer. I need a good...
View ArticleMesh creation
Hello, I have a problem with mesh generation. I set up the model and then mesh it. but when I want to run the study at first step it re-generate the mesh. I don't know what is the reason. my model...
View ArticleThermoelectric Effect - Adding the physics
Hello, I'm working in a project on thermoelectric generator. As 'Thermoelectric' physics interface,is not in the physics area/physics list, I was trying to add the physics using the steps given in the...
View ArticleTransport of concentrated species, Membrane gas separation
I've attached simplified model describing transport of the one component through membrane. I've made it simple to make you catch a problem easily. In my advanced model I'm using Laminar Flow physics...
View ArticleShape optimization of radiating plate
Dear all, I'm currently optimizing the shape of a vibrating plate in an closed hollow cylinder filled with air to get an as straight as possible wavefront. I model it 2D axisymmetric and make use of...
View ArticleNelder-Mead method in optimization module
Hello, I'm wondering if the Nelder-Mead method is also available in the optimization module? I can find it in the optimization node of a study, but not in the optimization module if it was added as...
View ArticlePort Phase
Hi all, I have a question about the port phase in rf module. I noticed that the software accepts 'i' as an argument for the field "port phase". what does that do? if I'im using multiple ports what is...
View ArticleElectromechanics in COMSOL
Hi, I am a student and I have just started using COMSOL. I would like to find out the displacement of a cantilever beam (2-DIMENSIONAL) due to electrostatic force created when 10V of voltage is applied...
View Articlecone in liquid
i have a question about the wetting of the cone in liquid: can i see the meniscus hang on the cone surface?? thanks
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