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Rising velocity - 3D single bubble

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Old   June 19, 2019, 04:03
Unhappy Rising velocity - 3D single bubble
  #1
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John
Join Date: Mar 2019
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Hi all Foamers,

I've done a simulation about 3D single bubble rising , now i want to compute rising velocity over time of bubble . Can you suggest me someway i can do it. I make some simple code but it seems like the "center position of bubble" always equal in each time step .

Any help is really appreciated. Thank you so much for reading

Code:
 y = 0.0;
      sumM = 0.0;
      sumMY = 0.0;

      forAll(alpha1, cellI){
        // Integration of {mass}
          sumM += (1-alpha1[cellI])*mesh.V()[cellI]*rho2.value();

          // Integration of (mass*height)
          sumMY += (1-alpha1[cellI])*mesh.V()[cellI]*rho2.value()
            *mesh.C()[cellI][1];
          
        }

        y = sumMY/max(sumM, SMALL); // Center of bubble but it always the same at each timestep
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Old   December 14, 2019, 16:13
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Wenjun Tuan
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Have you solved this problem ? How you use the cell-centre velocity ?

Quote:
Originally Posted by thintn222 View Post
Hi all Foamers,

I've done a simulation about 3D single bubble rising , now i want to compute rising velocity over time of bubble . Can you suggest me someway i can do it. I make some simple code but it seems like the "center position of bubble" always equal in each time step .

Any help is really appreciated. Thank you so much for reading

Code:
 y = 0.0;
      sumM = 0.0;
      sumMY = 0.0;

      forAll(alpha1, cellI){
        // Integration of {mass}
          sumM += (1-alpha1[cellI])*mesh.V()[cellI]*rho2.value();

          // Integration of (mass*height)
          sumMY += (1-alpha1[cellI])*mesh.V()[cellI]*rho2.value()
            *mesh.C()[cellI][1];
          
        }

        y = sumMY/max(sumM, SMALL); // Center of bubble but it always the same at each timestep
wenjuny is offline   Reply With Quote

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