RAO from Nemoh data

Discussion in 'Software' started by ThiagoMarinho, Apr 11, 2022.

  1. ThiagoMarinho
    Joined: Aug 2010
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    ThiagoMarinho Junior Member

    I need to produce an RAO and looking through nemoh's source code it seems that it does provide an RAO in post processing but the closest I could find was an excitation force RAO. I'm about to go through the route of generating the RAO from the added mass and damping coefficients, but even that is not trivial as the data output header is quite ambiguious.

    Is there anyone here who has been able to extract RAO data from nemoh results that could share some insight with me?

    Kind regards,
    Thiago
     
  2. Dolfiman
    Joined: Aug 2017
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    Dolfiman Senior Member

    Have you try the Nemoh team "contact us" directly :
    CONTACT US
    For questions, comments or bug reports, please leave a post on NEMOH’s forum: http://lheea.ec-nantes.fr/redmine/projects/nemoh . You must register first (http://lheea.ec-nantes.fr/redmine/account/register). In case of problems with your account activation, please send an email to adrien.grellier@ec-nantes.fr

    For other queries, you may contact Dr. Aurélien Babarit, 95cac7f8-a20e-4da8-9814-7132214faf63@ec-nantes.fr" class="lien_externe">aurelien.babarit@ec-nantes.fr
     
  3. ThiagoMarinho
    Joined: Aug 2010
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    ThiagoMarinho Junior Member

    I've tried the forum, but apparently it is offline as I get an error when clicking the link. I'll try emailing Aurelien directly. Thanks for the tip.
     
  4. Ais
    Joined: Aug 2022
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    Ais New Member

    Hi,
    I am also trying to obtain RAO data from NEMOH Results. Could you solve it?
    Could anyone here help?
     
  5. Dolfiman
    Joined: Aug 2017
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    Dolfiman Senior Member

  6. ThiagoMarinho
    Joined: Aug 2010
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    ThiagoMarinho Junior Member

    Hello mate,

    I have not written a manual on it. The values are given in dimensional format.

    Added mass and damping from RadiationCoefficients.tec
    Excitation from ExcitationForce.tec

    RAO equation
    RAO[i,:] = exc[:,i,0] / np.sqrt(np.power(freq_rad,2)*np.power(Brad[i,:],2) + np.power(-1*np.power(freq_rad,2)*(M+Arad[i,:])+C,2))
    Arad = Addded mass coefficients
    Brad = Damping coefficients
    exc = Excitation forces
    M = Inertia matrix
    C = Restoring coefficient Matrix
    freq_rad = frequency vector
    i = DOF index

    let me know if this is enough. If you speak python I can send you a script.
     
  7. Ais
    Joined: Aug 2022
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    Ais New Member

    Thank you so much. I shall try this. Kindly send me the python script also, either here or to my mail id aiswariaaa@gmail.com.
     
    Last edited: Aug 10, 2022

  8. Ais
    Joined: Aug 2022
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    Location: India

    Ais New Member

    Hi,
    Could you please explain, from where or how you have got 'C = Restoring coefficient Matrix', values?
    Also, it will be really helpful if you provide me with the python script to my email id aiswariaaa@gmail.com.

    Thank you so much,
     
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