Particle Reflection and Separation
Dear DualSPHysics developers and experts,
I am currently simulating the fluid flow inside a complex geometry - in contrast to wave simulations this is a more microscopic topic I guess. The fluid runs into the geometry and splashes onto a wall. At the wall most of the fluid gets separated resulting in some single particles and some groups of particles (like drops) falling down onto the bottom because of the gravity. At this wall I even noticed a strong separation and a strong reflection of the fluid particles. Besides a lot of particles get eliminated from the simulation because of their calculated density.
The situation on the bottom of the geometry is shown in the following video. I apologize for the bad visibility and quality but this is the only view where you can see rudimentarily what I mean.
I observed several approaches to weaken the particle separation, reflection and elimination because I want to see the fluid flow on the bottom of my geometry. By now I just had limited success. At first I thought this is a problem of particle distance (and so the number of fluid particles) - but the more particles I simulate, the more particles reflect and separate !
I assume that this is a problem generated by the dynamic boundary conditions. As long as the fluid particles are far away from the boundary particles there is nothing wrong. When the fluid particles approach the influence domain of the boundary particles their magnitudes change massive (especially density, vorticity and pressure) leading to the demonstrated behavior. Of course this massive change is required for modelling the wall but in my case the calculated flow pattern seems to be very unrealistic.
Is there a known workaround or solution to this reflection / separation problem without changing the viscosity formulation or the viscosity value ?
Regards
I am currently simulating the fluid flow inside a complex geometry - in contrast to wave simulations this is a more microscopic topic I guess. The fluid runs into the geometry and splashes onto a wall. At the wall most of the fluid gets separated resulting in some single particles and some groups of particles (like drops) falling down onto the bottom because of the gravity. At this wall I even noticed a strong separation and a strong reflection of the fluid particles. Besides a lot of particles get eliminated from the simulation because of their calculated density.
The situation on the bottom of the geometry is shown in the following video. I apologize for the bad visibility and quality but this is the only view where you can see rudimentarily what I mean.
I observed several approaches to weaken the particle separation, reflection and elimination because I want to see the fluid flow on the bottom of my geometry. By now I just had limited success. At first I thought this is a problem of particle distance (and so the number of fluid particles) - but the more particles I simulate, the more particles reflect and separate !
I assume that this is a problem generated by the dynamic boundary conditions. As long as the fluid particles are far away from the boundary particles there is nothing wrong. When the fluid particles approach the influence domain of the boundary particles their magnitudes change massive (especially density, vorticity and pressure) leading to the demonstrated behavior. Of course this massive change is required for modelling the wall but in my case the calculated flow pattern seems to be very unrealistic.
Is there a known workaround or solution to this reflection / separation problem without changing the viscosity formulation or the viscosity value ?
Regards
Comments
Please email us to dualsphysics@gmail.com with more details and we will look into the case since it seems very interesting and challenging for the DBCs
Regards