"DensityDTvalue"

Dear developer,

Good afternoon.


Please, this is not clear for me:

What term of the right side of the Equation below receives the value 0.1 (DensityDTvalue), presented below?

<parameter key="DensityDTvalue" value="0.1" comment="DDT value (default=0.1)" />


The Equation is in the literature:

Domínguez, J.M., Fourtakas, G., Altomare, C. et al. DualSPHysics: from fluid dynamics to multiphysics problems. Comp. Part. Mech. (2021). https://doi.org/10.1007/s40571-021-00404-2


Thanks so much.

Best regards.

Comments

  • That would be the "delta" in that equation. "h" is the smoothing length, "c" speed of sound of particle a, in DualSPHysics basically a constant. The rest are the terms.

    Kind regards

  • Dear colleague,

    Thanks for your response.

    I also had this suspicion.

    It is a dimensionless constant.

    Regards.

  • Page 136 of XML_GUIDE_v5.0.pd in DualSPHysics_v5.0\doc\guides

  • Thanks, Alex.

  • hi you all,

    I note that the defult value of DensityDTvalue is 0.1. Can i change it to another value, such as 0.01? Does it affect the simulation result stongly?

    Kind regards,

    Lucy

  • The value is based on details studies conducted by the developers of the so-called delta-SPH formulation.

    You can find more information here:

    Antuono M, Colagrossi A, Marrone S, Molteni D. 2010. Free-surface flows solved by means of sph schemes with numerical diffusive terms. Computer Physics Communications, 181 (3), 532-549.

    Antuono M, Colagrossi A, Marrone S. 2012. Numerical diffusive terms in weakly-compressible SPH schemes. Computer Physics Communications, 183 (12), 2570-2580.

  • Thanks, Alex.

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