Small flow problems
I am simulating the behavior of a fluid passing through the interior of a cavity of a cylinder, a wall of the cylinder gives energy to the fluid, has been modeled by non-isothermal flow and applying...
View ArticleLorentz force and moving mesh
As shown in the EM plunger example (www.comsol.com/model/electromagnetic-plunger-36671), Lorentz forces on translating objects can be modeled in Comsol with moving mesh nodes. However, the plunger...
View ArticleUndefined Value Found
I was runing a 2D model and came up with this error.. anyone can help me?? Undefined value found. - Detail: Undefined value found in the equation residual vector. .There are 912 degrees of freedom...
View ArticleUndefined value found
I had great trouble meshing a geometry. After I refined the mesh and was finally able to mesh it, I clicked the compute button. 78 seconds later, I got this message: Undefined value found. - Detail:...
View ArticleInducing torque at the ends of a deformed, imported 3D beam geometry
Hello everyone, I was hoping for some ideas on how to induce a bending moment or torque on a deformed geometry that I have imported from a previous study. The geometry is a relatively large (~1m long)...
View ArticleBuoyancy Force
Hello everyone, I know that there was a discussion about buoyancy forces acting on a rigid body but i spent some time for solving this problem and I will appreciate if you help me about my situation....
View Article2D corona Discharge
Hi everyone i'm trying to simulate corona discharge between two electrodes in comsol 5.2 the mesh is triangular with boundary layer mesh. i have built my model based on the example in the software's...
View Article(5.1 acoustics) Error Division by zero. - Function: /
Hi guys, I try to use pressure acoustics and thermoacoustics for no mean flow muffler simulation. No matter in 2D or 3D, comsol 5.1 always gives the error: [in 3D case] Division by zero. - Function: /...
View Article2D Meshing: Mapped vs Triangular
Hello, I am solving a corona discharge problem with a 2D axisymmetric domain shown in the attachment. No convergence was achieved when using the Triangular mesh, but convergence was achieved when using...
View ArticleConverting FEM mesh from COMSOL .mphtxt file to *.node format
Hello Dears I would like to kindly inquire about the possibilities of converting FEM mesh from COMSOL .mphtxt file to NIRFAST *.node format. As NIRFAST is an open source FEM-based matlab package for...
View ArticleModeling of busbars
Greetings to the whole community, I am currently working on the simulation of a busbar (made of three parallel drives). But I can not get good results (my expected results are different from those...
View ArticleSuper simple geometry- self intersection when meshing 5.2.a
Super simple geometry created using sweep-command The mesh wont work - self intersection! I really don't understand how I should create this geometry, is there something I don not understand when it...
View Articlemesh plot during time evolution
Hello everyone, in a 2D model I'm using the 'Moving Mesh' functionality with a time-dependent solver, but I do not know how to display the mesh displacement versus time: can someone help me? Thanks in...
View ArticleHow to deal with discontinuous heterogeneous data in 2D geometry
I am trying to model two phase flow in a 2-D porous media. There are four types of sands in the domain and thus four different entry capillary pressure. The variation of the capillary pressure becomes...
View ArticleAcoustic element?
Hi, Does COMSOL allows the user to select the type of elements used in the model? For example, in Abaqus, acoustic elements are available. Thank you. -- Regards, Linus Ang
View ArticleDisplacement of a point or node within global coordinate frame
Hello community. I'm able to access displacement (component x) of a point by using "evaluation at a point functionality" as part of postprocessing. This displacement seems to be defined within the...
View ArticleSkin friction drag in simulation of external flows in 3D slender objects
Dear COMSOL community, I am performing 3D external flow simulations at high Reynolds numbers (10^6 - 10^8) using RANS turbulence models such as SST. I am trying to validate the turbulence models and...
View Articlereacf(V)
Hi, Does anyone know precisely how reacf(V) is computed? COMSOL uses it to give a more accurate computation of flux then standard methods. I cannot find it documented in detail anywhere.
View ArticleMesh convergence in in acoustic module
Hello, I know that for acoustic models, at least 5-6 mesh per wavelength is required. I have done a parametric sweep study which changes the mesh density from 2 to 20 mesh per wavelength. The problem...
View Articlemesh order
Hello good, I am modeling the flow inside the half cylinder which there is an element inside that we want to cool, the cylinder has a thick part, in total we have 3 domains, to make the mesh I use one...
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