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Lumped Port S-parameters > 1 w/circuit interface @ port

Good day, This is a problem I have been dealing with for a while. I have a fairly basic setup involving 2 coupled antenna. I have extracted my desired S-parameters from my system in question, and have...

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Fail to evaluate variable. (material.epsilonr13)

Hello, I would like to calculate the electric field within a chamber with gaseous xenon filled out all the space. In the meanwhile, there is another hollow cylinder inside the chamber which is made up...

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capture the value of a variable at some specific time step

How can we capture the value of a variable at some specific time step to conserve it for later computation. How do we call the variable lets say temperature at the time t=100sec ?

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Mesh Generation error

In my geometry, am using one very thin PDMS of size 10 nm. All other layers thickness are between 0.1 to 100 um. I am getting intersecting face element error only for this layer. If I keep the...

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Overpotential Definition

In the user guide for the electrochemistry branch, overpotential is often defined as the difference between electric and electrolyte potential and the reversible potential, i.e. eta = phi_s - phi_l -...

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Changing units of geometry for an imported model

Hi, I hope some body could answer the following questions. Is it possible to change the units of geometry for an imported model ? If yes then is it possible to get desired units in "Cut Line 3D "...

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Problem with weak form-SBC

Hello to everyone, I am new to Comsol (i use the3.5a version) and i try to implement an SBC using the weak formulation in a simple structure in order to learn the weak form.Perhaps I have not...

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Using multiple components simultaneously

Hello, I am wondering what would be the best solution to the problem described below. If anybody has some tips or hints, I would be very grateful. I want to simulate an electrostatic beamline, which...

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Error in user-defined function

Hi everybody, I would like to use the PDE mode to solve a coupled problem of heat transfer and fluid flow in a porous media under freezing. I have three dependent variables : temperature, liquid...

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Importing One *.mph geometry into another *.mph file

Hi All; I want to import *.mph geometry into another *.mph model. Example: You create a model for single phase flow. Now you want to use the same geometry for two phase flow model. You do not need to...

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PML problem in groove waveguide

Hi, I have been trying to simulate the radiation pattern of a small dipole inside a groove carved into a gold substrate (transversal shape is triangular). The simulation box is rectangular, and I set 4...

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2D-Axisymmetry not considered for domain probes in the calculation "Average"...

Is the 2D-axisymmetry not considered in the calculation of domain probes? I learned, that I had to check the checkbox "Compute Integral in revolved geometry" when I wanted to calculate the correct...

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How to limit time step size, when time depend solver neglects Nyquist Theorem?

I have a boundary condition: Boundary Temperature varies as: 293.15[K] + sin(t/100[s]) * 1[K] The Time Dependend Solver generates a time series beginning with 0,1,10,20,40,80,160,320,640,1280 ... where...

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Checking continuity equation

Hello, I'm currently modeling incompressible flow with the Navier-Stokes equations in a Y-shaped pipe with newtonian properties (a fluid similar to water). My problem emerges when I try to check the...

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Single Turn Domain in 3D

Have anyone used the "Single Turn Domain" in 3D? I'm doing something research about eddy current and the influence of the environment(change of temperature) in 50kHz in a conductor in a magnetic field,...

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modeling nanostructured organic solar cell with Comsol

Hi,how can I modeling Zinc oxide nanostructures organic solar cell in which include the effects of optical interference, exciton diffusion, charge separation via the formation of polaron pairs, and...

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geometrical optics

hello, I need to plan a system that include a parabolic mirror. I'm OK with the parabola's geometric , but don't know how to define it as a mirror. I mean how making that an incoming plane wave...

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Laminar flow of Carreau fluid with variable density

Hello, I am using the Laminar flow physics together with the Carreau fluid properties and I was trying to write a formula for the density as a function of pressure 'p'. From my experimental data I have...

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Compressible Navier-Stokes with Non-newtonian viscosity in PDE module

Hello, I am new to COMSOL and I've been trying to model some incompressible Navier-Stokes system with variable viscosity, a Carreau viscosity to be specific. I have used the CFD module to model this...

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Truss interface - excitation

Hello, Since I read that the truss interface can only sustain axial forces, does anyone know if I could do a frequency domain study and excite the system by a transverse force? thanks, Nicolas T.

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