Skip to content

Effect On Particle Due to Fluid Density Change

OpenLB – Open Source Lattice Boltzmann Code Forums on OpenLB General Topics Effect On Particle Due to Fluid Density Change

  • This topic has 3 replies, 2 voices, and was last updated 6 months ago by jan.
Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
    Posts
  • #8111
    Jijo
    Participant

    Hello OpenLB community,

    I am currently working on thermally heated resolved particles.I have been investigating whether these particles are influenced by changes in fluid density, particularly in relation to the Boussinesq approximation. I experimented with such test case but I can not notice any effect on the particle’s velocity when including this effect. Any idea on such scenario?

    Regards,

    #8113
    jan
    Participant

    Dear Jijo,

    gravity is applied as a (constant) external acceleration, see accExt and apply_gravity in examples/particles/dkt2d. So the changes of the fluid density don’t affect the particle.

    Also, currently the external acceleration is defined for the whole particle system. Updating it within the ParticleManager would therefore update it for all particles. In your particular case, I think it would be best to manually apply the gravity at each timestep. For example, you could evaluate the density at the current particle position if an averaged density is sufficient. If you need different forces on the surfaces, then a more sophisticated approach would be necessary.

    Best regards,
    Jan

    #8117
    Jijo
    Participant

    Dear Jan,

    Thank you for your reply. I appreciate your constant support and help. The problem I am having is that the fluid itself is not flowing upward due to natural convection and I think such issue is due to the force field.

    It seems that the porousparticleBGK dynamics does not contain a force field and I believe that buoyancy forces are coupled using Boussinesq forces by the Guo forcing scheme. What do you think I should do in this case?

    Regards,

    #8119
    jan
    Participant

    Dear Jijo,

    if you solely need a force field for the coupling, then perhaps try PorousParticleKupershtokhForcedBGKdynamics and see if that works.

    Best regards,
    Jan

Viewing 4 posts - 1 through 4 (of 4 total)
  • You must be logged in to reply to this topic.