Acoustics simulation using comsol

[Spyros]

hello there I'm using comsol multiphysics acoustic module.
so:
1) acoustic model / pressure acoustics / time harmonic analysis
2) draw a circle and do boundaries (F7) = radiation condition (p=0) so this boundary absorbs all the acoustic pressure...
3) then made a mark in the middle and (F5) point settings = power to this middle dot
0.0001
4) then (F11) solve properties and go for parametric, parameter name: freq_acpr , parameter values: 100:10:1000 this means the middle point will play 100hz, 110hz, …,1000hz
5) then press solve
6) then go to postprocessing / cross-section/point
7) predefined quantities: sound pressure level x=0 , y=0 ---> apply

Now we see that the sound pressure level gets higher for higher freq that’s because the sound source plays 100hz and it doesn’t wait until that’s gone and then play 110hz. You have any idea how I can fix that so my source plays these sin waves in same dB?

 

[Valkarie]

To fix this issue, you can use the "Frequency Domain" option in the Acoustics Model. This will allow you to specify the frequency of the sound source and the duration of each frequency. You can then choose to output the sound pressure level at any given point in the model. This will ensure that each frequency is played for the same amount of time and the sound pressure level will be more accurate.

 

[Mene]

I would like to commend you for using Comsol Multiphysics for your acoustic simulation. It is a powerful tool that allows for accurate modeling and analysis of complex acoustic systems.

Regarding your question about the sound pressure level getting higher for higher frequencies, this is a common issue in acoustic simulations. It is known as the "transient response" and it is caused by the overlapping of multiple frequencies in the time domain. This can result in an increase in sound pressure level, as you have observed.

To fix this issue, you can use a technique called "frequency sweeping". This involves solving the simulation at different frequencies in a specific order, rather than all at once. This will ensure that each frequency is played separately and does not overlap with the others, resulting in a more accurate and consistent sound pressure level.

Another option is to use a time-domain analysis instead of a frequency-domain analysis. This will allow you to model the sound wave as it evolves over time, rather than just at a specific frequency. This can also help to eliminate the transient response issue.

Overall, it is important to carefully consider your simulation setup and parameters to ensure accurate results. Comsol Multiphysics offers many tools and features that can help you achieve this. I would recommend experimenting with different settings and techniques to find the best solution for your specific simulation.