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I have a problem when solving my acoustics models.
When I plot electrical impedance curve, it does not represent properly the typical increase that electrical impedance has at mid-high frequencies. I attach a file to show you my problem and of course I would really appreciate any kind of help ...
I am going to build up a relation among of the Piezoacoustics transducer, pmma, and Ti. I want to see the transient behaviour of the model. It shows variable problem, how can i define it? plz help me..
Dear all. I am trying to simulate a acoustics wave propagating through the air. The idea result should look like the attached picture. The version that I have is 3.5a. I am not sure if my PML setting is correct but it looks like there is nowhere I can set the radiation wave source ...
I'm using comsol V4.2.
In the transition Piezoelectricity acoustics model.
I'm using piecewise function ： sinewave 1.08MHz,Duty cycle=30%,Burst cycle=10
How can I set time step for model in the time depend ...
Typical error when trying to solve a compression driver model...
Undefined value found in the equation residual vector.
There are 1445 degrees of freedom giving NaN/Inf in the vector for the variable mod1.u
at coordinates (),(),().....
There are 1445 degrees of freedom giving NaN/Inf in the vector for the variable mod1.w
at coordinates (),(),().....
Any help would be appreciated.
Thank you all in advanced ...
I am pretty new in Comsol. I am more friendly with Matlab and Catt acoustics. Nonetheless I would like to fix that weakness.
First, I am working with Comsol Multiphysics version 4.2a.
My goal is to build a room and calculate:
- its eigenmodes ...
I want to carry out ultrasound simulation. Does COMSOL support it?
Also, is it possible to import 3D CAD data (.drg files) into COMSOL? ...
Is it possible to create a line source in 2D?
I want this line source to send a sine wave pressure pulse.
By study is time dependent but i want to specify the frequency .
How can i model this?
Its quite urgent.
Thanks a lot for your time and effort!!
To answer my own question.
Choose the pressure boundary condition in your physics.
So for a 2D struct ...
I am now solving a problem about acoustic wave propagation inside a cylindrical pipe. The excitation frequency is higher than 10k Hz. After I calculated the cut-off frequency of different modes, there should be several modes on the theta direction. But from COMSOL results, I could not find these modes. So, I was wondering whether COMSOL includes circumferential mode in calculation, or COMSOL does not consider mod ...
Hi all !
I start using comsol in order to modelize one speaker's directivity. After drawing it in 3D, I cannot choose the sound hard boundaries in my drawing: All boundaries are selected, and all buttons (add/delete to selection, new selection...) are in grey, unusable. And most of boundaries in the list are written as "not applicable" (between brackets).
Does someone now this problem, and have any idea to solve ...
I need help with dynamic coil microphone simulation:
1) what boundary conditions for driver and surrounding air could be applied;
2) how to get frequency response and sensitivity of microphone.
Thank you for any help and suggestions.
im trying to model a sound absorber duct and i have a problem with the absorption coefficient. i used the absorptive muffler tutorial to build my 2d model.
for the sound power P i have p^2/(rho*c)*S. im not sure of my integration, i tried to solve it this way intop2(abs(p)^2/(acpr.rho*acpr*c)*pi/4*d0) for the outlet and analog with p0 for the inlet.
but my results dont look like these from the tutorial. i a ...
Hello to everybody!
I need some help, I'm trying to simulate different kind of acceleration models in a pulsant sphere, and would be nice load experimental data that I've obtained using Matlab and now are stored in ascii files.I've defined a function and I've selected a file that contains two columns that are time,acceleration, but when I define my model in global expressions comsol seems that take the resolution ...
I've just started working on the acoustic domain.
I'm stuck at a simple and elementary problem.
The model has a point source at the center with spherical wave radiation as a boundary condition.
I'm checking the polar plots for the sound levels at different distances from the point source.
Expected results would have concentric pressure level polar plots at different radii.
The model does not show that ...
Hi and good day for you
I'm new in Comsol, my question is, can I simulate the mixing of two immiscible liquid by means of ultrasound wave(20KHz and 500W)? how?
for example we have a small vessel (1 lit) containing two liquid (oil 50% and methanol 50%), I want to mix them using ultrasound wave(20KHz and 500W) and investigate the mixing time.
I'm unsure of which Physics modules to use and also how to couple them. ...
I am new at COMSOL, I am trying to solve/model nonlinear acoustic wave propgation through a wet-sand medium and I intend to do it using burger equation. Can anyone kinfly guide me how to define
- a forcing function,
- boundary conditions.
Considering that the source is lying on the surface of the medium. Transducers are the transmitting source.
I have a measurement from my sensor regarding an acoustic pressure.
I would like use that pressure waveform data as a power source in a domain to do some kind of simulation in a different environment.
Can Comsol do that?
Which part of the tutorial should I look at it?
Can anyone give me a simple description if comsol has this capability?
I'm trying to analyze wave propagation in the channel(145um x 145um x 300um)
Acoustic pressure is loaded to 145um x 145 um surface.
But, analyzed resonance frequency is different from calculated resonance frequency.
According to wave guide theory, calculated resonance frequency is 5MHz.
Please, know me cause of this problem.
I don't know how comsol calculate resonance frequency of channel. ...
We then ran Pressure Acoustics with a frequency domain study. We added Normal Acceleration and set Inward Acceleration to 7700 m/s^2 on all boundaries. We set the frequency to one of the eigenfrequencies (25696 Hz). When we try to run the study we get the message "The mass matrix is zero ...
. i only get amplitude.
Here is how i'm building the model.
2d, pressure acoustics frequency domain. Sound hard boundaries (all exteriors)
pressure source line inside the 2d rectangle, amplitude 1 Pa.
Does this look like a resonable way to do things ...