showCases FallingDroplet running result negative pressure

Good morning everyone, I have been running the multiphase flow model which is Fallingdroplet. I used the recommended parameters and there are two problems in this model

  1. the kinetic energy becomes -nan after 1200 time step.
  2. the pressure at the interphase is negative value.

Does anyone has the same problem? thank you you guys very much

Hello,

the fallingDroplet example uses the two phase module of Palabos (src/multiPhysics/twoPhaseModel3D.h*). Unfortunately, Palabos v1.5r1 has a bug in this model, which is corrected, so in the upcoming Palabos release (sometime in the first half of 2017) the instability you observe will not appear any longer. We would recommend that you use the freeSurface model instead (which will also get an upgrade in the new release). We apologize for the inconvenience…

Best,
Dimitris

Thank you very much!

Hello Dimitris: I tried to use the free surface model in the fallingDroplet3d, but when I switch TwoPhaseFields3D to FreeSurfaceFields3D, all the computer density and velocity gives me errors.
Im not sure if it’s like this (easy change) or I need to do more changes.

if integrateProcessingFunctional is necessary as well?

In addition could there be 2 lattice in the free surface model? because I need 2 fluid.

Thank you very much!