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Help for opening comsol4.3
Hello comsolers, I have a project which is created by Comsol4.3a or 4.3b (I don't know exactly) and I have comsol4.3. As far as I know comsol4.3 can not open the projects that are created in newer...
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Moddeling change in resistance/conductance due to thermal expansion
Dear Comsol users, Due to temperature a material expands and when it does the electrical resistance of this material also changes. I want to model this in comsol. I added the thermal expansion first,...
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Normal B boundary condition
Is it possible to define a normal B boundary condition in Magnetic field-No currents? My idea is to simulate the top half of the geometry, which is enough due to symetry in some problems. Thank you.
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MATLAB LiveLink
Hi! I am trying to model a smart material called Magnetorheological Elastomers. It can change it's stiffness when a magnetic field is present. To do this, I would like to use a MATLAB function that can...
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COMSOL giving me wrong Ks value!
Hi, I am using the Richards Equation interface and there is an equation relating kappa (permeability) to k (hydraulic conductivity) which is written in the documentation but I have calculated by hand...
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Automatize Simulations and Changing Parameters
Hello, I have a very simple model of two thin cylinders which are separated by a certain distance and each have a certain diameter. I then measure the voltage inside a volume, where each cylinder plays...
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Trigonometric functions
How can I set trigonometric functions to give me the correct value from an angle given in degrees, I mean, if I'm using the expression STL*cos(73.7), with STL=524 mm and 73.7 is an angle given in...
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diffusion convection issues
Hi, I want to simulate the concentration variation of nano-particle in a micro-fluid channel under magnetic field, and to show nano-particle will build up in the region near the magnet. I have built a...
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Attaching beam to surface (edit: coupling beam and structural mechanics)
Hi all, I asked a similar question recently, but I have another question about working with beams. I am trying to make this object swing using these beams to hold it up. I have made some beams, drawn...
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data sets; Heat Transfer
Hi COMSOL user's I'm trying to model the heat transfer in a set of detectors connected to some electronics components that consume Watts. My geometry in three dimensions is complicated and it requires...
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Information carried by 'Initial values' in solid module
Hi there, My project is to simulate the solid deformation in two steps. In each step, one solid module is solved. In the 2nd step, I specify the initial displacement field and velocity field are from...
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importing data to comsol
Hi everybody It is possible to import data from a txt file to a 1D plot group? I'm trying to compare two functions, for instance, the temperature vs. time, coming from different projects, and I would...
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Gravity flow from an atmospheric tank
Hello community!! I'm in a license trial of COMSOL to verify its capabilities to our simulation requirements. We have an open roof tank at the top of a hill; it is filled by a pipeline with constant...
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Problem with calculating the stiffness of a magnetic bearing, using the...
Hi I am a student in electrical engineering, and I am very new with COMSOL multi physics. I have got this project where I am to design a magnetic bearing with permanent magnets. To do this, I want to...
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Bidirectional coupling of "Conductive media DC" with " Heat Transfer by...
Hi I am coupling "conductive media dc" to "heat transfer with conduction" to see the effect of electrical conductivity due to thermal heating and vice versa. In the "heat transfer with conduction"...
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linking progress variable to other variables
Hi, Im trying to create a model for a project, my current model is adiabatic but im adding heat loss through enthalpy. What i want comsol to do at this stage, while i have the following: a progres...
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error using SiO2 as dielectric material in mosfet
Hi, I am getting following error when using SiO2 as dielectric material in mosfet. Undefined value found. - Detail: Undefined value found in the equation residual vector. There are 90 degrees of...
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Ramp and Step function
Hi all, Does the step1(t[1/s]-10) means that function value becomes 1 after 10 seconds on condition that the step1 is defined as the step function? Does rm3(t[1/s]-10) means that the function value...
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Model convergence dependent on mesh quality, confused!
Hi all, My COMSOL model only solves when the mesh size is "above" the predefined Normal size. When I increase the mesh resolution to "Fine" or higher, the step BiCGStab in the progress tab stalls at...
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Solid mechanics/ Thermal expansion
Hi, I'm trying to simulate stress induced by thermal expansion (as a result from femtosecond laser). - My geometry is simply just an ellipse placed inside a rectangle. (please see the attached) -...
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