first off: I am very impressed with the capabilites and usability of acousto. I have a relatively complex simulation setup for sound propagation in a closed duct. My "geoms" statement is a list of multiple MSH entries and a few geometrical primitives. Now I would like to assign properties such as radiance/impedance to some of the surfaces. I have trouble understanding how to assign properties to mesh surfaces. I can modify the radiating box tutorial and see some principles but there are only primitives in this file and no meshes and it is not enough to continue on my own. How will acousto order the mesh surfaces if there are multiple geometries? How do the index numbers in the .panels files correspond with the surfaces?
Thanks in advance
Last edit: mathias 2017-03-31
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thanks for using acousto. The way to provide different properties to different boundaries of a complex geometry with acousto 1.6 is a little bit cumbersome, we admit. What you want to do is possible, but for very complicated geometries can be painful. I suggest you to wait version 2.0, that we plan to release by the end of next week. It is ready, and we are completing the fundamental tests. One of the major improvements of the new release is exactly what you need.
Umberto
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custombc=2; # boundcond type gmsh
gmshbc=["floor", "wall", "ceil"];
floor={
tag = 13;
re_lambda = 1.0;
im_lambda = 0.0;
re_gamma = 0.0;
im_gamma = -23.813;
# re_f = real part of f ;
# im_f = imaginary part of f ;
};
wall={
tag = 14;
re_lambda = 1.0;
im_lambda = 0.0;
re_gamma = 0.0;
im_gamma = -23.813;
# re_f = real part of f ;
# im_f = imaginary part of f ;
};
ceil={
tag = 15;
re_lambda = 1.0;
im_lambda = 0.0;
re_gamma = 0.0;
im_gamma = -23.813;
# re_f = real part of f ;
# im_f = imaginary part of f ;
};
I have Acousto 2.0 and the original example: Room_Acoustics is working fine...
Perhaps you can see directly an error, or perhaps there is a working example with custombc=2 ?
Thanks in advance
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Dear Max, if you would provide me the input files set you are trying I'll be glad to help you!
All the best
Giorgio
Il 29 apr 2021 16:08, Max Funk <mf3@users.sourceforge.net> ha scritto:
Hello Umberto Iemma,
many thanks for your program...
I tried to convert the tutorial: Room_Acoustics to the new boundary conditions custombc=2 with the physical tags of the gmsh file.
But now I get an error message:
2021-04-29 15:33:56 DEBUG [1/1] modsolinfo->custombc=2
2021-04-29 15:33:56 DEBUG [1/1] Allocating 24 for sizeof(struct phystag)*config_setting_length(phystagcont)
2021-04-29 15:33:56 INFO [1/1] n physical tags = 3
2021-04-29 15:33:56 DEBUG [1/1] reading physical tag [floor]
2021-04-29 15:33:56 ERROR [1/1] You must provide a valid physical tag
I tried many things, but cannot find the reason, the .msh file is looking fine:
custombc=2; # boundcond type gmsh
gmshbc=["floor", "wall", "ceil"];
floor={
tag = 13;
re_lambda = 1.0;
im_lambda = 0.0;
re_gamma = 0.0;
im_gamma = -23.813;
# re_f = real part of f ;
# im_f = imaginary part of f ;
};
wall={
tag = 14;
re_lambda = 1.0;
im_lambda = 0.0;
re_gamma = 0.0;
im_gamma = -23.813;
# re_f = real part of f ;
# im_f = imaginary part of f ;
};
ceil={
tag = 15;
re_lambda = 1.0;
im_lambda = 0.0;
re_gamma = 0.0;
im_gamma = -23.813;
# re_f = real part of f ;
# im_f = imaginary part of f ;
};
I have Acousto 2.0 and the original example: Room_Acoustics is working fine...
Perhaps you can see directly an error, or perhaps there is a working example with custombc=2 ?
In the boundary condition I have two frequencies... There is also the question, if I would calculate e.g. a frequency response, does the program make an interpolation for the frequency dependent boundary condition?
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
no, at the moment the user is responsible to provide a number of boundary conditions equal to the number of frequencies to evaluate for each bc group (floor0, floor1, ... walls0, walls1, etc. in your case), or to provide a non frequency dependent bc for each group (floor, walls, etc.)
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
all the physical tags present in the msh file must be defined in the cfg file:
modsol={ # solver module [...]
gmshbc=["ceil%d", "floor", "wall"]; (OR gmshbc=["ceil%d", "floor%d", "wall%d"]; depending if you want to have frequency dependent impedances from all the boundaries or not) [...]
}
and consequently structures defining the relative bc
ceil0={ [...]
};
ceil1={ [...]
};
wall={ [...]
};
floor={ [...]
};
I attach you a "working" cfg. I used "working" as I did not wait for the run to finish, but it started the evaluation 😉
I investigated further custom boundcond 2 and everything is fine when the number of frequencies nome =... equals the number of boundary conditions, e.g.
Hello Max,
I made a couple of tests and dug into our commits.
The bad news is that you found a bug of acousto2.0.
The good news is that it had been already discovered some time ago while we were developing acousto, and it is fixed in the v2.5, which is going to be released very soon.
At the moment, a way I can imagine to overcome the issue is to let custombc=2 to write a the bc files with nome=1, and then use custombc=1 with wathever nome.
All the best,
Giorgio
Last edit: Giorgio Palma 2021-05-19
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Hallo Giorgio,
many thanks for your investigation and your reply :-)
It's valuable to see that custombc 2 does no more than writing the boundcond file and then performing the same as custombc 1
I have now created the boundcond with a simple script file; perhaps it could be attached to the RoomAcoustics tutorial; I attach it below...
As a feedback, I wanted to say, that at the moment I prefer custombc=0 because in a simple calculation I need just a frequency-independent absorption coefficient, which I do not get with a frequency-independent custombc=1 or 2...
Ideally it would be like this:
1) one could give either impedance or lambda/gamma/f (with default always hard wall)
and then
2) one could provide this with a definition in the .cfg file, with a separate .panels file or with physical tag in the mesh file
To summarise, at least I would strongly recommend not to remove the simple boundary condition custombc=0 from the program, as was announced in the user guide...
Given the developments to acousto over the last few years (and I think someone mentioned a change in direction?) is it worth my while to modify the current code to fix whatever is causing it to abort (possible double free during shutdown which did not prevent testing) and, more importantly, modify the user interface to better support engineering studies.
Also I note that project development has taken place for several years outside the public repository. Is this way of working likely to continue into the future?
The above is not intended to be a criticism. It is good to see an open source acoustic BEM code that has not been lost to "C++" tendencies. Many years ago when I worked in academia the university and/or sponsors owned the copyright to software and something like this was not possible. The university was happy to transfer copyright back to the authors for papers but not software which they considered to be of financial value. Of course they had no workable way to do anything with the value they claimed to see but that's academia for you.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hello,
first off: I am very impressed with the capabilites and usability of acousto. I have a relatively complex simulation setup for sound propagation in a closed duct. My "geoms" statement is a list of multiple MSH entries and a few geometrical primitives. Now I would like to assign properties such as radiance/impedance to some of the surfaces. I have trouble understanding how to assign properties to mesh surfaces. I can modify the radiating box tutorial and see some principles but there are only primitives in this file and no meshes and it is not enough to continue on my own. How will acousto order the mesh surfaces if there are multiple geometries? How do the index numbers in the .panels files correspond with the surfaces?
Thanks in advance
Last edit: mathias 2017-03-31
Mathias,
thanks for using acousto. The way to provide different properties to different boundaries of a complex geometry with acousto 1.6 is a little bit cumbersome, we admit. What you want to do is possible, but for very complicated geometries can be painful. I suggest you to wait version 2.0, that we plan to release by the end of next week. It is ready, and we are completing the fundamental tests. One of the major improvements of the new release is exactly what you need.
Umberto
Hello Umberto,
thanks for your quick reply! I will gladly wait for revision 2.0 then.
Mathias
Hello Umberto Iemma,
many thanks for your program...
I tried to convert the tutorial: Room_Acoustics to the new boundary conditions
custombc=2with the physical tags of the gmsh file.But now I get an error message:
I tried many things, but cannot find the reason, the .msh file is looking fine:
and the boundcond section of the .cfg file
custombc=2; # boundcond type gmsh gmshbc=["floor", "wall", "ceil"]; floor={ tag = 13; re_lambda = 1.0; im_lambda = 0.0; re_gamma = 0.0; im_gamma = -23.813; # re_f = real part of f ; # im_f = imaginary part of f ; }; wall={ tag = 14; re_lambda = 1.0; im_lambda = 0.0; re_gamma = 0.0; im_gamma = -23.813; # re_f = real part of f ; # im_f = imaginary part of f ; }; ceil={ tag = 15; re_lambda = 1.0; im_lambda = 0.0; re_gamma = 0.0; im_gamma = -23.813; # re_f = real part of f ; # im_f = imaginary part of f ; };I have Acousto 2.0 and the original example: Room_Acoustics is working fine...
Perhaps you can see directly an error, or perhaps there is a working example with
custombc=2?Thanks in advance
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Dear Max, if you would provide me the input files set I'll be glad to help you and solve the problem!
Last edit: Giorgio Palma 2021-04-29
Hallo Giorgio,
thank you, that's a great offer :-)
I include the project files below...
In the boundary condition I have two frequencies... There is also the question, if I would calculate e.g. a frequency response, does the program make an interpolation for the frequency dependent boundary condition?
no, at the moment the user is responsible to provide a number of boundary conditions equal to the number of frequencies to evaluate for each bc group (floor0, floor1, ... walls0, walls1, etc. in your case), or to provide a non frequency dependent bc for each group (floor, walls, etc.)
Last edit: Max Funk 2021-05-07
Thanks for the info.
Last edit: Max Funk 2021-05-07
Dear Max,
I found two problems in the acousto input file:
modsol={ # solver module
active=1;
[...]
}
ceil0={
tag = 15;
re_lambda = 1.0;
im_lambda = 0.0;
re_gamma = 0.0;
im_gamma = -23.813; # alpha=0.25, f=325Hz
};
modsol={ # solver module
[...]
gmshbc=["ceil%d", "floor", "wall"]; (OR gmshbc=["ceil%d", "floor%d", "wall%d"]; depending if you want to have frequency dependent impedances from all the boundaries or not)
[...]
}
and consequently structures defining the relative bc
ceil0={
[...]
};
ceil1={
[...]
};
wall={
[...]
};
floor={
[...]
};
I attach you a "working" cfg. I used "working" as I did not wait for the run to finish, but it started the evaluation 😉
All the best,
Giorgio
Da: Max Funk mf3@users.sourceforge.net
Inviato: venerdì 30 aprile 2021 17:12
A: [acousto:discussion] 852635@discussion.acousto.p.re.sourceforge.net
Oggetto: [acousto:discussion] Radiant/impedant/custom boundary condition panels with GMSH inputs
Hallo Giorgio,
thank you, that's a great offer :-)
I include the project files below...
Attachments:
Radiant/impedant/custom boundary condition panels with GMSH inputshttps://sourceforge.net/p/acousto/discussion/852635/thread/e3a67dc9/?limit=25#3fe3
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Hallo Giorgio,
thank you for the reply and the help
That was it, I didn't see that the definition of the custombc had to be outside the modsol structure....
Now it calculates well :-))
Hallo Acousto team, Giorgio,
I investigated further custom boundcond 2 and everything is fine when the number of frequencies
nome =...equals the number of boundary conditions, e.g.gmshbc=["wall%d",...]; nome=3; ... wall0={...}; wall1={...}; wall2={...}; ...or
gmshbc=["wall",...]; nome=1; ... wall={...}; ...However, if
nomeis greater than the number of given conditions, even with frequency independent conditionsgmshbc=["wall","ceil", "floor"]; nome=3; ... wall={...}; ceil={...}; floor={...};then it is crashing with an error
Is this a given restriction? In that case, no frequency response analysis would be possible without writing huge numbers of boundconds, e.g.
nome=100; ... wall0={...}; ... ... ... wall99={...};Perhaps it is a bug from my side or from the software? I attach the project... with
nome=1it works fine, withnome=2it is crash...thank you Max for your precious work. I'll investigate this and come back with something as soon as possible!
Hello Max,
I made a couple of tests and dug into our commits.
The bad news is that you found a bug of acousto2.0.
The good news is that it had been already discovered some time ago while we were developing acousto, and it is fixed in the v2.5, which is going to be released very soon.
At the moment, a way I can imagine to overcome the issue is to let custombc=2 to write a the bc files with nome=1, and then use custombc=1 with wathever nome.
All the best,
Giorgio
Last edit: Giorgio Palma 2021-05-19
Hallo Giorgio,
many thanks for your investigation and your reply :-)
It's valuable to see that custombc 2 does no more than writing the boundcond file and then performing the same as custombc 1
I have now created the boundcond with a simple script file; perhaps it could be attached to the RoomAcoustics tutorial; I attach it below...
As a feedback, I wanted to say, that at the moment I prefer custombc=0 because in a simple calculation I need just a frequency-independent absorption coefficient, which I do not get with a frequency-independent custombc=1 or 2...
Ideally it would be like this:
1) one could give either impedance or lambda/gamma/f (with default always hard wall)
and then
2) one could provide this with a definition in the .cfg file, with a separate .panels file or with physical tag in the mesh file
To summarise, at least I would strongly recommend not to remove the simple boundary condition custombc=0 from the program, as was announced in the user guide...
Best regards and thank you for the program - Max
Given the developments to acousto over the last few years (and I think someone mentioned a change in direction?) is it worth my while to modify the current code to fix whatever is causing it to abort (possible double free during shutdown which did not prevent testing) and, more importantly, modify the user interface to better support engineering studies.
Also I note that project development has taken place for several years outside the public repository. Is this way of working likely to continue into the future?
The above is not intended to be a criticism. It is good to see an open source acoustic BEM code that has not been lost to "C++" tendencies. Many years ago when I worked in academia the university and/or sponsors owned the copyright to software and something like this was not possible. The university was happy to transfer copyright back to the authors for papers but not software which they considered to be of financial value. Of course they had no workable way to do anything with the value they claimed to see but that's academia for you.