Giving Conduction Its Own τ Left Viscous Heating Stuck at Pr = 1 — The Quasi-Equilibrium g* in Two-Population LB
In Couette flow a plain two-τ thermal LB keeps θ_max at 1.000 for every Pr. Adding the quasi-equilibrium g* recovers 0.498, 0.710, 1.000, and 1.997.
A 1 μm Aluminum Particle Heated 4.6× Slower Than the Continuum Formula — Sherman Interpolation in the Knudsen Transition Regime
At 1500 K and 1 atm a 1 μm aluminum particle sits at Kn = 0.67. Nu = 2 shortens heat-up by 4.58; Sherman's harmonic mean puts that time back.
Deriving μ and k from One Formula Put Pr Off by 1.98× — the 9/4 Behind a 123.5 K Wall Temperature
Deriving μ and k from one mean free path pins air's Pr at γ = 1.400 against a measured 0.707. Eucken's 9/4 drops the Couette wall gap from 123.5 K.
Refining the Grid 8x Never Moved 2.4674 — Two Constants Fourier Left Behind in 1807
The convergence objection that got Fourier's 1807 memoir rejected comes back on today's grids as two stubborn constants: 8.9490% and pi^2/4.
Doubling τ Left Pr at 1.0000 — The Two Constants Locked Inside Thermal LBM
A single-distribution thermal LBM ties viscosity and thermal diffusivity to one τ, locking Pr at 1. I measured on D2Q9 what a second distribution unlocks.
Why Laundry Dries at 5 °C — Diffusion-Limited Evaporation vs. Heat-Driven Boiling
Laundry dries at 5 °C because the interface vapor fraction is not zero. Boiling waits on heat, and the Lee coefficient r is a penalty, not a property.
Measure the Drag, Get the Heat Transfer — The Reynolds Analogy
At Re_x = 1e5 on a flat plate, Cf/2 stays at 1.050e-3, and St times Pr to the 2/3 matches that value at Pr = 0.7, 1, and 7.
Heating It Hotter Made It Cooler — The Boiling Curve and Critical Heat Flux
Zuber's CHF for water at 1 atm is 1.259 MW/m². Rohsenow's nucleate flux reads 1.094 at 20°C and 3.692 at 30°C, already past that ceiling.