Virtual buffer inlet

Geometry and definition

There at three aspects to the geometry:

• A cylindrical extrusion that makes up the whole
• A shorter cylindrical extension within the latter defining the fade-in region, Has same radius, normal, but shorter length and an origin shifted by half-a-cell + epsilon = Of
• A virtual buffer in an another universe. Has same cylindrical radius but opposite normal. It's origin is Ov

There are five main aspects to the inlet operation:

1. LB makes request to the buffer for a particle
2. The buffer teleports as many particles as requested and can fit within physical fluid inlet
3. The buffer updates its origin Ov.
   • Ov should be such that a new particle can be introduced if possible. Where conditions below do not apply first, this means Ov should be set such that the next particle that can be introduced is hovering over the fluid domain, ready for insertion.
   • The particles that are fading in should not see a brutal change in node-node interaction with virtual particles. In other words, if fading-in particles r_i are interacting with virtual particles, then Delta Ov * normal =< min(Delta r_i * normal)
   • The next particle to introduce must not hover beyond a certain point. For instance, it cannot hover over the vascular system, otherwise it would be introduced directly there without fading-in. So this puts constraint on Ov + r_next where r_next is the position of next cell to be introduced.
4. Virtual and Physical cells interact!
5. Additional cells are added to the buffer, if necessary.