Exterior field sum

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Hi,

I'm trying to optimize the far-field pattern of multiple acoustic sources (an array of sorts) by tweaking their phases. Rather than simulating the whole thing over and over, I think it could be smart to calculate the radiation of each source individually at first, and then simply calculating the exterior field based on the sum of these with various phases applied. Is this possible?


3 Replies Last Post 15 avr. 2026, 13:52 UTC−4
Acculution ApS Certified Consultant

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Posted: 9 hours ago 15 avr. 2026, 07:17 UTC−4

If you are doing a frequency sweep, then there is an assumption of linearity. When linearity holds, you can sum up individual parts of several sources, and you can change the phase (and magnitude) of each of them as you please, so just apply a unit input and adjust in post-processing. But, if the sources have an associated impedance, then that needs to be included for each study. So, if you apply a displacement/velocity/acceleration condition on one active source, then all other sources (passive) can be hard walls, which is anyway the default. For other source types, there is more to it. This is equivalent to Thevenin/Norton approaches to electrical sources.

-------------------
René Christensen, PhD
Acculution ApS
www.acculution.com
info@acculution.com
If you are doing a frequency sweep, then there is an assumption of linearity. When linearity holds, you can sum up individual parts of several sources, and you can change the phase (and magnitude) of each of them as you please, so just apply a unit input and adjust in post-processing. But, if the sources have an associated impedance, then that needs to be included for each study. So, if you apply a displacement/velocity/acceleration condition on one active source, then all other sources (passive) can be hard walls, which is anyway the default. For other source types, there is more to it. This is equivalent to Thevenin/Norton approaches to electrical sources.

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Posted: 3 hours ago 15 avr. 2026, 12:57 UTC−4
Updated: 3 hours ago 15 avr. 2026, 12:57 UTC−4

Thanks! Indeed, the other sources are hard walls and I have no issues summing the pressure fields from individual sources, but summing the exterior fields (efc1.pext by default, to be clear) does not work properly. I can do BEM or extend the computational domain in FEM but both options are pretty much slower than a smaller FEM domain with EFC

Thanks! Indeed, the other sources are hard walls and I have no issues summing the pressure fields from individual sources, but summing the exterior fields (efc1.pext by default, to be clear) does not work properly. I can do BEM or extend the computational domain in FEM but both options are pretty much slower than a smaller FEM domain with EFC

Acculution ApS Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 3 hours ago 15 avr. 2026, 13:52 UTC−4

Thanks! Indeed, the other sources are hard walls and I have no issues summing the pressure fields from individual sources, but summing the exterior fields (efc1.pext by default, to be clear) does not work properly. I can do BEM or extend the computational domain in FEM but both options are pretty much slower than a smaller FEM domain with EFC

What is the problem with the exterior field? It has phase information in it.

-------------------
René Christensen, PhD
Acculution ApS
www.acculution.com
info@acculution.com
>Thanks! Indeed, the other sources are hard walls and I have no issues summing the pressure fields from individual sources, but summing the exterior fields (efc1.pext by default, to be clear) does not work properly. I can do BEM or extend the computational domain in FEM but both options are pretty much slower than a smaller FEM domain with EFC What is the problem with the exterior field? It has phase information in it.

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