Fluids

Fluids

VOF-to-DPM multiphase model

    • soloviev
      Subscriber

      Hello,


      I am using the VOF-to-DPM multiphase model to study spray droplets in hurricane conditions. Initially, I have a domain that the bottom half is water and the top half is air. A strong wind is applied either as an inlet condition or as stress along the top of the domain. As the wind propagates into the domain, waves and then droplets form.  When the droplets meet the size and asphericity criteria, they become Lagrangian particles in the DPM model.


      As I understand from the webinar, the injection in DPM is a “placeholder” for when the droplet becomes small enough to transition into DPM. Do the properties in the DPM model apply to the Lagrangian particles once they are formed? Specifically, do the Lagrangian particles interact with the other fluids (the air and remaining water)?


      Thank you,


       


      Alex

    • seeta gunti
      Ansys Employee

      Hello Alex,


      You are right! Once the droplets meet the size and aspherity criteria, the droplet will be converted to DPM injection and tracked through lagrangian tracking. 


       


      Regards,


      Seeta 


       

    • DrAmine
      Ansys Employee

      Dear Alex,


      Yes the injections are placeholder and all settings, physics and boundary conditions you apply for the Discrete Phase will be then deployed once the model transformation kicks in and droplet are passed from the Eulerian formulation to the pure Lagrangian framework.

    • soloviev
      Subscriber

      Hello Amine,


      Thank you for this update.


      Just to clarify, when I turn on the "Interaction with Continuous Phase" option in the Discrete Phase Model, this means that the droplets will be interacting with both the air and water in the domain that are a part of the VOF model? Is that correct?


      Thank you,


      Alex

    • Rob
      Ansys Employee

      They'll interact with the primary phase, I think DPM will see the secondary phase as an increase in drag but won't recombine. Please check DOC re DPM and VOF.

    • DrAmine
      Ansys Employee

      As we are solving for bulk flow in the one fluid formulation then the interaction will be with the bulk. In DPM there is no volume displacement so there is no influence of the particles volume there. 


       


      A phase based tracking is only available for Eulerian model with some constraints.

    • seeta gunti
      Ansys Employee

      I hope we answered your query.  let us know if you have further questions. If not, can you make the thread as resolved.


      Regards,


      Seeta


       

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