Current density and resistance in piezoelectric device
I am trying to simulate the current density in a piezoelectric device. The geometry is a simple rod with a fixed boundary (also ground boundary) and a surface load on the opposite boundary. I can...
View ArticleSurface growth and moving mesh (ale) ?
Hi, I am building a CVD growth model using the heavy species transport, much similar to the silane growth model. My geometry includes a small trench (um scale), where I deposit the material. Is it...
View Article"Error: Duplicate variable name."
I am using solid mechanics, electrostatics and moving mesh and I want to perform an Eigenfrequency Study. The solver crashes with an error message:"Error: Duplicate variable name." But I didn't find...
View Articlestability of geometry creation
Suppose that the geometry is not simple enough to be represented by regular geometry primitives. Then, there are two chooses: 1- use of parametric surfaces (possible as external function) 2- use of...
View ArticleCalculating contact area
Is there any way to calculate the contact area of a contact pair within COMSOL (ie without having to post-process data in MATLAB, which I have yet to try)? I have tried surface integration and other...
View ArticleUnphysical solution with ellipsoid/sphere vs. hemisphere
Having a problem with COMSOL providing unphysical solutions when I use a sphere or ellipsoid "hovering" above the bottom of a domain as opposed to a hemisphere. I have a box, and within the box is a...
View ArticleS-Parameter in Complex format in COMSOL
I have not yet been able to find how COMSOL represent complex format of S-parameters. Can anybody please provide the correct format with reference? I am wondering if it is like S11=Re(S11)+j*Im(S11) or...
View ArticleHow to incorporate varying temperature with respect to time??
As the ambient temperature varies with time, I wish to add that variation pattern of temperature in COMSOL 4.3a. Is it possible? If possible, how can I add 1. using equations 2. using excel sheet for...
View ArticleRoot mean square in 4.3a
Hi I need to calculate the Root mean square (RMS) of a voltage. Are there any predefined functions in Comsol to do so. I searched the docs and got no clue on that. Thanks a lot
View ArticleLicensed number of users already reached
Hello, I couldn't open the versions 4.2a and 4.3 from COMSOL. A message informing me that the number of users already reached and the program closed automatically. It seems strange for me, because...
View Article2D electrostatic Force
Hi, I am modeling a slice of a simple comb capacitor in 2D. I would like to determine the force acting on the fingers. I can calculate the electric field, but when I try to determine the force through...
View ArticleIs the problem positive definite? Floquet periodic boundary conditions or PML...
Hello, I am doing some elastic wave simulations using solid mechanics module and piezoelectric module. And sometimes the DOF of my models are quite large so that I have to choose the solver manually to...
View ArticleHow to rotate a 2D Plot?
I built a model with a 3D geometry. Unfortunately the created 2D plot (postprocessing), which is based on a cut plane, is rotated by 90°. Is it possible to rotate the 2D plot back by 90° or to exchange...
View ArticleWhat physics do I need to model clogging of a vein? (very similar to...
If I have a species entering a vein at some velocity, how would I model the reaction with the surface and thereby build up of particles on the wall? I know I need some mass transfer equation (let's say...
View ArticlePoint Charge
Hello all I want to define point charges (lets say some circles as positive Or negative charges) in Comsol. Can anybody give me some idea how i can do this? what I have in my mind is: define a constant...
View ArticleUsing interpolation to define temperature-dependent material properties
Hi, I am a COMSOL beginner. Trying to added a file containing temperatures and measured material properties and then utilize an interpolation function to define the temperature-dependent material...
View ArticleHow do I make a laser on z-axis in 2D modeling?
Hi, I did 2D modeling in Electromagnetic waves, Transient mode. I wanna make a model in which the enhanced electric field is shown when a laser passes from air to nanopattern. however i don't know how...
View ArticleMAKING STRIATIONS IN A SOLID CYLINDER
how do i make striations in a solid cylinder? I know it should be possible but some how cannot figure out how?
View ArticleHow to enter the temperature that varies with time??
Due to the variation in air velocity, the external temperature varies with time. Can I know how can I input the values using an equation or an excel sheet??
View Articlevoltage at different coordinates
Hello every one. it is possible in COMSOL to fine the voltage at (x,y,z) coordinates? thank you
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