Result is triangular, should be cosine wave
Hello all, i am trying to simulate magnetic flux induced by a multi-turn coil with current as coil excitation. Now that should be no problem but i want to do it in the time domain for a couple of...
View Articledynamic or static pressure?
Hi, I have a simple "problem" when using the "free and porous media flow" physics. The pressure that is calculated during the calculation is the total pressure p=p_dyn+p_stat (p_dyn=dynamic pressure...
View Articlewhat physics to use
Hi all, i am trying to implement this paper but and i dont know how to calculate the time response and phase response of the signal and how to apply this input signal. please help
View ArticleLast Time Step is not Converged.
Dear Experst I am doing time dependent FSI and i am applying sinusoidal pressure but always i am facing the same problem that is last solution time step not converged. Even Comsol is not solving the...
View Article'Java exception occurred' error
I use COMSOL 4.3a with Live link for MATLAB The version of MATLAB is 7.10.0 (R2010a) Some times, irregularly, when I run m file with COMSOL live link for MATLAB, 'java exception error' occurred. I...
View ArticleLorentz Force calculation
I want to simulate the displacement of an current-carrying wire due to an external magnetic field, due to the Lorentz Force: vect{F} = I(current) * vect{l(legth)} x vect{B}. The geometry is 3D. I'm...
View ArticleLiquid Crystal - Director distribution
Hello, I would like to calculate the director distribution of liquid crystals. The formula fs=1/2(K11*(div n)^2 + K22*(n * rot n + q0)^2 +K33* |(n x rot n)|^2) describes the Oseen-Frank free energy...
View Articleelectrospray simulation
Hi, I'm trying to simulate an electrospray experiment using comsol 4.1 in order to see the formation of droplets leaving a needle to a plate. A high voltage is applied on the needle and the plate is...
View ArticleMissing Infinite Element Domain
I cannot find the Infinite element domain node, which I thought was under Definitions. I'm using the Heat Transfer in Solids in the base package. If it is not available there, where could I find it?
View ArticleCOMSOL Releases COMSOL Multiphysics version 4.3a
We at COMSOL are proud to introduce version 4.3a of COMSOL Multiphysics to the COMSOL community See: www.comsol.com/products/4.3a/ This introduces: * LiveLink™ for Excel® * LiveLink™ for Solid Edge® *...
View ArticleDielectrophoresis
Hi there. I tried to observe the particle movement effect through the "particle tracing for fluid module". However, the result of particle trajectories didn't show up any particle movement. Please...
View ArticleCutting a simple geometry in half
I'm trying to cut a relatively simple 3D geometry in half. My approach is to first partition the geometry using a work-plane and then delete the entities that I don't want. Unfortunately, some parts of...
View ArticleAccessing database
Hello, Is it possible to access the database of a study and modify the value of a dependent variable? I am running v4.3b with Matlab. In my Comsol model, I have two studies; general form PDE and...
View ArticleHow to cut a geometry
Hello, I have a 3D geometry and I need to cut half of it to create a symmetry plane. Can you please describe the steps. Thanks. Regards, Dimitris
View ArticleIdentifying Acoustic Shape of Sound Localization
New to this forum. I am a researcher but limited in acoustic knowledge. Hoping you guys can help. Is it possible to identify the shape of a sound source? We are trying to identify whether the sound...
View ArticleProblem with Mesh Swept
There is something I don't get right with the Mesh Swept option. I used the model "biased_resonator_3d_modes.mph" from the Model Library as a starting point. There they built a mesh on one face of the...
View Articlelong running time
Hey: I hope you all are well, I have a question, when I run my model it takes lots of time to run and finally the analyses wouldn't be completed. and also no errors would be appeared. Now, I am not...
View ArticleVolume concentrations in transport of diluted species module
I am confused by the fact that the" transport of diluted species node" in COMSOL only lets me work with surface concentrations. I want to model a 3D problem that has a given volume concentration as...
View Articleproblem in inputting signal
i am working on SAW RFID using acoustic module with piezoelectric devices physics and i want to input a signal of type S= Acos(wt+p)rect(t/p) to the input IDT and i dont know how to do it .please help me.
View ArticlePointwise constraint in weak form
Hello, What is the meaning of the value of "Pointwise constraint" in Comsol? It is a strong, bidirectional constraint. If the constraint expression is "-x+1", then is the value of the variable "x"...
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