This is a 2D field view of the same SCWO physics as the 3D reactor tour: instead of watching individual particles fly down a tube, you watch two grid-based fields evolve. The top panel is a phase-diagram heatmap — every pixel is an independent evaluation of the water-density correlation at that (T, P) point, with your current operating point marked live. The bottom panel is a finite-difference plug-flow solve: the organic-waste concentration field C(x, t) is stepped forward on a 1D spatial grid using the advection–reaction PDE ∂C/∂t + u·∂C/∂x = −k·C, and each new profile scrolls down to build a position-vs-time waterfall — the diagonal destruction front you see is the same physics as the particle color-flip in the 3D version, just solved as a continuum field.
Plug-flow PDE: ∂C/∂t + u·∂C/∂x = -k·C
Steady outlet: C(L) = C0 · e^(-k·τ) → DE = 1 - e^(-k·τ)
Arrhenius rate: k = A·e^(-Ea / R·T)
Ea ≈ 125 kJ/mol, A ≈ 1.0×10^10 s⁻¹ (typical organics)
Water's density collapses from ~950 kg/m³ (liquid-like) toward ~120 kg/m³ (gas-like) across the critical region; the heatmap's color boundary is that transition, anchored to water's true critical point (374 °C, 22.1 MPa) with the pseudocritical line shifting to higher T as pressure rises above Pc. Dissolved inorganic salts lose solubility once density drops below ~300 kg/m³ and precipitate — modeled here as a mean-field relaxation of the precipitated fraction (equivalent to averaging many independent stochastic salt particles, verified numerically against that particle picture) and drawn as a growing deposit bar beneath the waterfall.
- Temperature / Pressure — set the operating point on the heatmap; together they fix water density and rate constant k.
- Residence time τ — sets the advection speed u = L/τ in the PDE; longer τ raises destruction efficiency for a given k.
- Excess O₂ ratio — sub-stoichiometric O₂ caps the effective rate constant regardless of τ.