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Modeling Membrane Permeability in a Coefficient Form PDE Model

Hello, I am trying to model diffusion of water through a cell modeled by a circle placed in the surrounding environment modeled by a square. I first tried out the model using natural boundary...

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Error function in geometry

Hello folks, I wanna to draw "erfc" function as an upper border for my geometry. Any idea ? Thank you in advance!

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electro-convection

Can Comsol solve an electroconvection problem? To clarify: a polar gas or liquid moves in nonuniform electric field. Thus, we need to solve for electrostatics, and the known field distribution will...

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Time difference

I am interesting in natural convection simulation. I have a problem of validation my COMSOL model where the time in the literature case differs from my model time . In another words, when I try to...

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vertical moving magnet in the air

hello dears, I want to simulate a moving magnet in the air and see how the magnetic field changes in the air.i used rotating machinary in 2d in the model navigator.i want to use assembly for my model...

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Near field/Far Field of scatered light from a nanoparticle

Hi,I am simulating in Comsol 4.2. In my simulation domain ,2 micrometer by 2 micrometer,the upper portion is air and the lower surface is glass.A nanoparticle of 300 nm is placed at the...

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cannot use old values as the initial values for new step

Dear sir or madam, I am using comsol to simulate a stationary model. I had convergence problems so that I was forced to vary the inlet BCs gradually to converge to the real case and I had to use the...

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cannot use old values as the initial values for new step

Dear sir or madam, I am using comsol to simulate a stationary model. I had convergence problems so that I was forced to vary the inlet BCs gradually to converge to the real case and I had to use the...

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cannot use old values as the initial values for new step

Dear sir or madam, I am using comsol to simulate a stationary model. I had convergence problems so that I was forced to vary the inlet BCs gradually to converge to the real case and I had to use the...

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cone-jet mode in electrostatic field

Hi, Here is my problem. I want to simulate a electrohydrodynamic (EHD) phenomenone , a nozzle with full water (or electrolyte) in a electrostatic field, the the water is polarized and deformed the...

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Magnetic Force on an armature

Hello I'm dealing with a very simple problem that has been very frustrating for me! I would appreciate if any one can assist me with that. I'm modeling an E-shaped core in 2D magnetic field module. It...

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Time integration in comsol 3.5a

Hi everyone, I am just wondering if there is a time integration function in comsol 3.5a. I am calculating fluid flow rate through a boundary and which is a function of time and I would like to...

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Physics for a elastomeric vibration isolator.

Good morning. I'm almost finished with my model. The model consists in : 1 - Base. ( Base ) 2 - Elastomeric Rubber. ( Borracha) 3 - Lid. (Tampa) 4 - Screw Hole.( Parafuso ) The Screw Hole receive the...

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thermal BC's across the interanl surface between the heat sink and air in the...

n Model Library : Heat transfer module : Tutorial models: heat sink . It is considered the temperature filed is continuous across the internal surface between the heat sink and the air channel. first...

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simulating a rotating and moving blade

hi, i want to simulate a blade that is both moving up, down, front and back and also pitching at the same time mostly with time varying velocities. i know i have to use mesh deformation but i dont know...

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Modelling of a permanent magnet

Hello everyone, I want to see the magnetic field lines from a bar shaped permanent magnet. I have created a rectangle and surrounded it with the air domain i.e a bigger rectangle. I have the following...

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Error - Failed to evaluate variable jacobian

Hello, I am currently working with the batteries and fuel cells module and I am attempting to create a model of a micro-scale PEM fuel cell. Right now I am starting by just trying to solve a free and...

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Moving Mesh and Variable Knudsen Diffusion Coefficient during CVD

Dear Forum Members, I am trying to simulate oxide deposition inside a 100 nm pore by using a 2D axisymmetric model. The model is similar to a heterogeneous catalysis problem and the only modification...

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2D patterns on 3D geometries

Hi, Is there any way to draw a 2D pattern on a surface of a 3D geometry in COMSOL 3.5(a). Suppose we have a block and on the top surface of this block we want to draw a 2D rectangle. Any suggestions?...

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failed to generate mesh for face

hello, i imported a solid geometry to comsol, but when i generate mesh i get error: failed to generate mesh for face, i tried to make custom mesh for these faces, but did not solve the problem. can...

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