Evaluating the radiated sound at microphone location

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hi Everyone, 

First of all a very happy new year...!

If anyone has any information regarding this problem, please do help

I want to find the sound radiated  from a stator motor at some distance from it.

So I formed a solid sphere around the stator and used boolean operation to separate stator from the sphere, so that it will form a hollow section in the sphere where the stator was first placed.

Now I meshed the sphere with 3D finite elements and used M10 card to specify it.

Then I meshed the outer boundary of sphere with infinite elements (CACINF3) to absorb the acoustic property there. 

I provided the material property to it as PACINF. 

I don't know how the PACINF card works. I can't find the help file on it either.

Is the above method right? 

Please guide me on this

 

Have a good year ahead

Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    Hi @Mayur Deshmukh

     

    Input Input for Acoustic Infinite Element analysis can be defined with the following information input by the user:

    1. Fluid material properties (bulk modulus, speed of sound, fluid density) can be specified for the fluid elements on the MAT10 Bulk Data Entry.

    2. Pole location (origin of the acoustic disturbance). Pole is the center of acoustic disturbance. This can be defined on the PACINF Bulk Data Entry via the XP, YP, ZP coordinates.

    3. The nodes defining the interface between the infinite and semi-infinite domain. This is defined as the Infinite elements (currently 3-noded CACINF3 and 4-noded CACINF4 elements are supported).

    4. The radial interpolation order can be specified via the RIO field on the PACINF entry.

     

    Modelling:

    1. The acoustic source can be defined as the Pole location on the PACINF entry.

    2. A minimum of 1 layer of Fluid elements should be defined on the surface of the structural domain of interest.

    3. The Infinite elements (CACINF3 and CACINF4) should only be defined on the topmost surface of the Fluid elements.

     

    You can find more information about PACINF from attached .doc.

     

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2018

    Hi sir,
    I have tried the above mentioned things and Still getting some errors as below.

     

    *** ERROR 1684: FLUID element      592 points to non-fluid GRID    781.
     *** ERROR 1684: FLUID element      592 points to non-fluid GRID    487.
     *** ERROR 1684: FLUID element      592 points to non-fluid GRID    486.
     *** ERROR 1684: FLUID element      592 points to non-fluid GRID    776.
     *** ERROR 1684: FLUID element      592 points to non-fluid GRID    869.
     *** ERROR 1684: FLUID element      592 points to non-fluid GRID    872.
     *** ERROR 1684: FLUID element      592 points to non-fluid GRID    871.
     *** ERROR 1684: FLUID element      592 points to non-fluid GRID    870.
     *** ERROR 1684: FLUID element      593 points to non-fluid GRID    869.
     *** ERROR 1684: FLUID element      593 points to non-fluid GRID    872.
     
    Can we have a web session where you can show a demo on this and I can get my doubts cleared

     

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2018

    Hi Mayur,

     

    Can you share the model file and .out file please?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2018

    Hi Mayur,

     

    Is stator component, structural or fluid type?

     

    I see some nodes have CD=-1 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2018

    Hi sir,

    I tried running the file you sent me. Now the following error is occurring 

    <?xml version="1.0" encoding="UTF-8"?>1514970332420-1480557203.jpg

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2018

    Mayur,

     

    Same file works for me without error. I had to abort the run as it is taking all my machine resource. 

     

    Which version of HyperWorks are you using?

     

    Can you share the .out file?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    HW 17

    The. out file is attached below

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2018

    Mayur,

     

    I ran the same file again and it is error free. Must be a problem with update.

     

    Please update the solver to latest (2017.2.2) and try again. 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2018

    I ran the file in the updated version 2017.2.2 and it is working fine. Thank you so much

  • Abhi05
    Abhi05 Altair Community Member
    edited March 2018

    Hi @Mayur Deshmukh

     

    Input Input for Acoustic Infinite Element analysis can be defined with the following information input by the user:

    1. Fluid material properties (bulk modulus, speed of sound, fluid density) can be specified for the fluid elements on the MAT10 Bulk Data Entry.

    2. Pole location (origin of the acoustic disturbance). Pole is the center of acoustic disturbance. This can be defined on the PACINF Bulk Data Entry via the XP, YP, ZP coordinates.

    3. The nodes defining the interface between the infinite and semi-infinite domain. This is defined as the Infinite elements (currently 3-noded CACINF3 and 4-noded CACINF4 elements are supported).

    4. The radial interpolation order can be specified via the RIO field on the PACINF entry.

     

    Modelling:

    1. The acoustic source can be defined as the Pole location on the PACINF entry.

    2. A minimum of 1 layer of Fluid elements should be defined on the surface of the structural domain of interest.

    3. The Infinite elements (CACINF3 and CACINF4) should only be defined on the topmost surface of the Fluid elements.

     

    You can find more information about PACINF from attached .doc.

     

    @Prakash PagadalaDo you have any video/tutorial or any webinar for this, or any link where we can understand radiated sound analysis simulation??

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited March 2018

    Hi Abhi,

     

    I will check and update you soon. 

  • Abhi05
    Abhi05 Altair Community Member
    edited March 2018

    @Prakash Pagadala

     

    Hi..........

    Did you find anything??

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited March 2018

    Hi Abhi,

     

    Have you gone through Acoustic Infinite Elements on OptiStruct help?

  • Abhi05
    Abhi05 Altair Community Member
    edited March 2018

    Hi Prakash,

    I cannot find Acoustic Infinite Elements..

    Acoustic Analysis is present and in that there are two options,

    Coupled Frequency Response Analysis and Radiated Sound Analysis.........

     

    Which are good enough to confuse me for Load Steps and assigning sets...

     

     

  • Abhi05
    Abhi05 Altair Community Member
    edited July 2018

    Input Input for Acoustic Infinite Element analysis can be defined with the following information input by the user:

    1. Fluid material properties (bulk modulus, speed of sound, fluid density) can be specified for the fluid elements on the MAT10 Bulk Data Entry.

    2. Pole location (origin of the acoustic disturbance). Pole is the center of acoustic disturbance. This can be defined on the PACINF Bulk Data Entry via the XP, YP, ZP coordinates.

    3. The nodes defining the interface between the infinite and semi-infinite domain. This is defined as the Infinite elements (currently 3-noded CACINF3 and 4-noded CACINF4 elements are supported).

    4. The radial interpolation order can be specified via the RIO field on the PACINF entry.

     

    Modelling:

    1. The acoustic source can be defined as the Pole location on the PACINF entry.

    2. A minimum of 1 layer of Fluid elements should be defined on the surface of the structural domain of interest.

    3. The Infinite elements (CACINF3 and CACINF4) should only be defined on the topmost surface of the Fluid elements.

     

    You can find more information about PACINF from attached .doc.

     

    @Prakash Pagadala,

    Can this be done in Hypermesh-2017 version or it requires any other latest version?
    Also, can this be carried out in Student license? 

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited July 2018

    Hi,

     

    Yeah, it can be handled with the current version and if the node count is below 100,000 you can use student edition.