Wildfire Smoke Plume (2D) — Buoyant Stable-Fluids Simulation

This 2D companion trades the 3D version's orbiting particle plume for a real fluid solver you can read the mechanics of directly: a coarse velocity/density/temperature grid runs a Jos Stam-style stable-fluids step — add source, buoyancy force, viscous diffusion, divergence-free pressure projection, semi-Lagrangian advection, project again — every frame. A fire-intensity slider controls the heat and smoke injected at the base, a wind-speed and wind-shear pair drive an altitude-dependent boundary-layer wind profile that bends the plume over as it climbs, and a viscosity/mixing slider and a grid-resolution control let you trade turbulent detail for a cleaner or coarser flow. The live readout cross-checks the simulated plume-top height against the Briggs (1975) buoyant bent-over plume-rise formula, so the numbers on screen are a physics sanity check, not decoration.