Why do we use particles for advection and grids for pressure correction?
the particle velocity stays the same, due to the fact, that the material derivative = 0 so no linear interpolation is needed
Explain PIC and FLIP!
Particle-in-cell (PIC) method uses interpolation to transfer
velocities from the grid to the particles; however the
method is highly dissipative
Fluid-implicit particle update (FLIP): update particles
velocities by the difference of the velocities before and
after projection
Given a cell with a particle inside. Which staggered grid face center receives the most contribution in a particle to grid transfer?
the nearest to the particle
What does FLIP miss compared to RPIC?
angular momentum
Which options do we have to represent a surface?
implicit, explicit
How do we convert from an implicit representation to an explicit representation?
marching cubes algorithm
Why do we need the ghost fluid method?
to enforce p=0 at the surface interface
FLIP particles are only definied in the liquid phase. What can we do if we need a velocity in the air interface, for example during interpolation from grid to particles?
extrapolate the velocities from the fluid to the air phase
What does the fractional boundary method improve over the standard voxelized boundaries?
the modified cells closer match the boundries
Name a solver for a symmetric positive-definite matrix!
conjugate gradient solver
Which problems does the cut cell algorithm address?
complex cases or in the presence of thin gaps smaller than one grid cell
Last changeda year ago