Calibration parameters in DualSPHysics

Hi all,

I'm reasonably new to DualSPHysics and I'm wonder if you more experienced users have certain parameters/constants that you usually adjust for calibration? Obviously things like gravity and density are generally set values, but are there any others that you would adjust to say calibrate water level and currents of a wave simulation?

Comments

  • In wave propagation we recomend:

    Visco (AV)=0.01

    Coefh=1.2 or 1.5

    dp=H/10

    Density difussion term (DDT)=2

    Symplectic integrator

    Wendland kernel

  • You are spot on @rhysomac - you have to look at currents and wave elevation to verify your case. As usual with numerical solutions, even if you believe you input a wave with say, wave height of 3 meters, then perhaps in your simulation it is actually 3.2 due to reflection with domain, domain size etc.

    Always have to go in depth with post-processing a simulation afterwards - this takes time but very valuable.

    What Alex is mentioning are general good tips, but do try playing around with values and get a deeper understanding. For an example some advanced questions would be:

    • Using artificial viscosity is okay in which cases?
    • What impact does coefh play, especially if I have an object in my flow domain?
    • dp = H/10, what if this ratio changes up and down?
    • Why DDT2, and not 1 or 3?
    • Why do we prefer the symplectic operator?
    • What influence does the kernel choice have on simulation?

    And there is not always a clear answer to these kind of questions, but my advice is to remember to be critical and write down / make a mental note of your mainfindings, atleast for your own sake

    Kind regards

  • Hi @Alex and @Asalih3d, thank you for your enlightening answers, I will take a lot from this advice. Cheers!

  • Hi @Alex  @Asalih3d and @rhysomac ,

    Would you mind telling me what the notation 'H' symbol in 'dp = H/10' means?

    Many thanks.

    Kind regards

  • H=wave height

  • Thank you for your reply😁

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