Lattice Boltzmann Fluid
Mesoscopic fluid simulation — streaming, collision, flow visualization
About: The Lattice Boltzmann Method (LBM) simulates fluid dynamics at the mesoscopic scale using a D2Q9 lattice (9 velocity directions per cell). Instead of solving Navier-Stokes directly, it evolves probability distributions of particles — each step comprises streaming (particles move to neighbors) and BGK collision (distributions relax toward Maxwell-Boltzmann equilibrium at rate 1/τ). LBM naturally handles complex geometries and recovers the incompressible NS equations in the low-Mach limit. The Reynolds number Re = UL/ν determines laminar vs. turbulent flow. Click the canvas to add/remove obstacles.