Dear Alhasan,

Unfortunately i deals with rotating blades and rotating zone should be considered in my study and i never found any thing a bout ffowcs williams and hawkings formula in openfoam. i don't know what should i do. if i didn't find any thing about fw-h in openfoam my study will stop.

please, can you suggest how i can solve this problem

Hi Eslam,

Search hard if some one has FW-H model written for openFOAM, its been there out too long both FW-H and OpenFOAM so some one should have written it at some point ?

If it is not necessary you have to use OpenFOAM, FW-H model is available in Fluent !!!

If not comes the complicated part where you have to write you own C++ codes for FW-H

you can start this by understanding the Curle's Equation and see how the model is written in OpenFOAM that is provided above, then you can try to understand FW-H equations and write your own.

- in my point of view writing a FW-H code for openFOAM and validation can be a BEng Dissertation by itself.

Best of Luck
Hasan K.J

Hi Alhasan,

thank you my friend, i will work hardly to implement this analogy in openfoam. any time if you found any thing about this topic, i will be grateful for informing me. :)

Best regards,
Eslam H. Mohamed

I have not understood your questions.

Acoustic analogy in openfoam
 

i want to ask for how to implement an acoustic analogy in openfoam. my study focus on noise emitted from wind turbine and as we know, there is no acoustic model in openfoam. any one know how to do this especially using ffowcs williams and hawkings formula.

Dear Ilya,

Thanks for sharing the code.

With the help of the notes given I could able to compile only the libraries (dynamically using wmake libso) but when I tried to link the main solver "libAcoustics" I am getting the following error.

In file included from /apps/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/OutputFilterFunctionObject.H:232:0,
from Curle/CurleFunctionObject.H:40,
from Curle/CurleFunctionObject.C:26:
/apps/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/OutputFilterFunctionObject.C: In member function ‘bool Foam::OutputFilterFunctionObject<OutputFilter>::ti meSet() [with OutputFilter = Foam::Curle]’:
Curle/CurleFunctionObject.C:40:1: instantiated from here
/apps/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/OutputFilterFunctionObject.C:219:9: error: ‘class Foam::Curle’ has no member named ‘timeSet’
make: *** [Make/linux64Gcc45DPOpt/CurleFunctionObject.o] Error 1
make: *** Waiting for unfinished jobs....

It would be nice if you could help me out to implement the solver properly..

Regards,

Sethu

Hi,
I saw that Professor Jasak made a OF-Summerschool anouncement
Adam Azenic: numerical simulation of the acoustic response in the edge tone simulation. Presenting a full non-linear acoustics solver
https://twitter.com/hrvoje_jasak/sta...93641565782017

Did you try OF 2.1?

Although it was mentioned in libAcou documentation that it was developed for OF 2.1 and later, i'd suppose to compile it for OF 2.1

Dear Ilya.,

Yes, it did work well for OF 2.1.0. I could able to compile all the solver codes and libraries in it. I also notice that "OutputFilterFunctionObject.C" file in OF 2.2.2 has got significant changes in it while revision. I dont know how to resolve this issue. But, I will proceed now with OF 2.1.0 to solve the test cases and some of my trail cases.

Thanks for your help. If you have any further updates on this solver, do let us know.

Regards,

Sethu

why?
 

did you not add in Curle/Curle.C
"
void Foam::Curle::timeSet()
{
// Do nothing - only valid on execute
}
"

and in Curle/Curle.H
"
//- set time
virtual void timeSet();
"
It compiles on openfoam 2.2.0 then

Dear Ilya and all,

Thank you so much for sharing the information.
From the presentation material ( OFW-Seoul-Kraposhin-AcousticTrack-5 pdf) given for Curle implementation discussed in slide 9 the expression used for
acoustic pressure is p'= 1/4IIc0_ * x/r^2 *[ (df/dt) + c0 f/r].

But in the Curle .C at line 288
scalar coeff1 = 1. / 4. / Foam::constant::mathematical:: pi / c0_ / c0_ ;

forAll (observers_, iObs)
{
SoundObserver& obs = observers_[iObs];
vector l = obs.position() - c_;
scalar r = mag(l);
scalar oap = l & (dFdT + c0_ * F / r) * coeff1 / r /r;
if (dRef_ > 0.0)
{
oap /= dRef_;
}
obs.apressure(oap);
}

}
}
It is clear that oap is the expression to find the p' value. But in the expression for oap, at the denominator we have c0_^2 , which is computed from the coeff1 expression. Is there any approximation made?Could you please explain is there any approximation like nearfield or farfield behind this approximation?

Thanks in advance.

Curle analogy code in OpenFOAM
 

Hello,

Unfortunately, the code shared by skeptic can't be downloaded anymore.

Could anyone (including skeptic) share it again? Thanks in advance.

Best Regards,

Delcraft

Quick answer:

• Current website location: http://openfoam-extend.sourceforge.n...l?Main=2&sub=1
• File in question: http://sourceforge.net/projects/open...n.tar/download

edit: Links for all of these workshops: http://openfoamwiki.net/index.php/Ha...FOAM-Workshops

Thank you! That's exactly what I want.

Delcraft

FW-H model in OpenFOAM required.
 

Hey @Eslam Hashem
How did your project go, did you implement the FW-H model in OpenFOAM yet or did you find any one else who has implimented any other acoustic anology other than Curles provided by @Ilya in OpenFOAM

Regards,

Hasan K.J

Updated Curle library
 

Hey all.

You can find updated libAcoustics with Curle analogue for OpenFOAM 2.3.0 through following link.

https://unihub.ru/resources/625

Thanks.

Thanks a lot for sharing this,

Eagerly waiting for the F-WH for openfoam if any updates please share with us,

Kind Regards,
Hasan K.J

how ??
 

thanks for the updates but I have a problem
How I can compile it, it seems to be precompiled because ther is (lnInclude) folder and (deb) files.
any one can help me to compile it
thanks in advance

Help
 

Please. any one can help me compiling this library

Quick answer:

1. Make sure you're using OpenFOAM 2.3. For example:
   
   Code:

   ---

   icoFoam -help

   ---

   Gives me this at the end:
   
   Code:

   ---

   Using: OpenFOAM-2.3.x (see www.OpenFOAM.org)
Build: 2.3.x-fdfc12484890

   ---

2. Download the ZIP file from the link in post #36.
3. Run as normal user the following commands:
   
   Code:

   ---

   mkdir -p $FOAM_RUN
cd $FOAM_RUN
cd ..
unzip ~/Downloads/libAcoustics.zip

   ---

   Note: Adjust the path "~/Downloads/libAcoustics.zip" to your needs.
4. Then run:
   
   Code:

   ---

   cd libAcoustics-2.3
./cleanLib.sh
./makeLib.sh

   ---

5. If all goes well, the last line shown on screen should be something like this:
   
   Code:

   ---

   '/home/ofuser/OpenFOAM/ofuser-2.3.x/platforms/linux64GccDPOpt/lib/libAcoustics.so' is up to date.

   ---