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Perforation Fins

Dear I'm a new user for COMSOL 4.2, so I need help in my project. How can I create a circular perforation in direction of flow through a pin fin as shown in attachment file. please, help me

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k-e turbulence equation in coefficient form PDE

Hi, I am working on gas solid fluidized bed in Euler-Euler model laminar flow Module. The run is fine. Now I want to add k-e turbulence equations in Coefficient form PDE and solve the problem with...

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24 slot stator of synchronous machine!

Hi, If we have 24 slot stator, how can we apply three phase excitation to stator. I know how to deal with 6 slot stator but 24 slots are creating confusion. Any help will be highly appreciated. Thanks!...

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Piezoelectric axis definition

Hi All, I have some questions regarding the piezoelectric physics in the COMSOL. I'm using COMSOL multiphysics 4.3 Correct me if I'm wrong, in 3D model, the axes are 1 (x) (horizontal axis), 2 (y) (out...

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why does "Undefined value found in the stiffness matrix" means?

I'm trying to simulate Photonic crystal. As far as I know, there is no need for me to know the stiffness of material in the crystal. However, when I click "compute", comsol always screen error message...

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Which surface the terminal voltage should apply to in the electrostatics...

I want to calculate the electric capacity between two metal plates then I do a model in comsol as follow: I draw two blocks with a 2µm gap between them,and the material of the two blocks are set to...

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coupling a 1D geometry with a 2D geometry.

Hi, I wanted to know if it is possible to couple a 1D geometry to a 2D geometry the way I want to. In fact I am trying to solve a 2D model, but at every point in this model I need to get the solution...

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Encountering error during meshing

when I try to run a mesh i encounter the following error message: "Edge is much shorter than the specified minimum element size." I do not know what this means and any advice on how to get rid of this...

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2D model coupling

I want to couple two 2D models, the first models computes a stationary state and the second should use the result to compute a time dependent model. I thought that with identity mapping I could read...

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Particle absorption and refraction

Hello. How to simulate refraction and absorption in Mathematical particle tracing module. Maybe I should add another physics. I could simulate reflection by choosing wall condition. Any suggestions?...

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Mesh dependency !

Hello, I wanted to ask about meshing a 3D problem. I'm doing a validation for 3D channel with radiation between the inner side of the channel (surface to surface radiation). I'm facing a problem when I...

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calculate resistance of a numeric multi turn coil in freqency domane is to high

Dear all, I hope anybody in this Forum have the same exipiriance width the multi turn coil damane. In my model i have a simple numeric multy-turn-coil domane. My problem is that the calculate...

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Time dependent boundary

Hi all, I have flow through a cylinder, and want the inlet velocity to be periodic [ u(r,t) ]. Im new to comsol and havent been able to find an answer to this. Thanks in advance for any help!.

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precipitation around grains in porous medium

Hi, I am trying to build a model where the idea is that after a chemical reaction CaCl2 + Na2CO3 => CaCO3 (s) + 2 NaCl. CaCO3 precipitate and is immobile. I am using the Reaction Engineering (re),...

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Implementation of boundary conditons at liquid-liquid interface

Hi all, I am simulating a liquid-liquid flow in a channel. The liquid-liquid interface appears to be curved as one phase liquid is dispersed as droplets. I have used the laminar flow single phase...

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Mass transport in tube.

Ok, so I solved the unsteady laminar fluid flow in the tube im looking at. Now, I want to add in a mass transport problem. Say I have a sphere of concentrated dye at the center of the tube, and want to...

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Hydrodynamic drag

Hi All, I am trying to simulate the hydrodynamic drag force on a particle of 8um suspended in a fluid which is flowing at a flow rate of 20uL/min through the micro-channel of 15umx15um entrance/exit...

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Problems with parametric sweep

I have a model that I want to investigate with differens values on at least one of the design variables. If I change the variables value manually and compute, there is no problem but if i use variable...

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Exporting Specific Mesh Data

I am quite new to Comsol so please excuse my ignorance when trying to explain my problem. I am currently working with a model of a redox flow battery, and I am interested in exporting data such as flow...

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Transmission Spectra in RF module

Hi, I'm a beginner in COMSOL. I am using the COMSOL scripting in MatLab. I would like to know how I can get the transmission spectra as shown in Fig 4 of the file attached below. I am looking to plot...

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