A Two-Cell Interface Loses 39% of Its Surface Tension — The Anisotropy of the Korteweg Stress
·6 min read
Across a flat liquid–vapor interface the normal pressure stays constant and only the tangential pressure dips. That dip is surface tension, and a dz=1 lattice loses up to 39% of it.
I Plugged in Pressure Directly and a Still Interface Started to Shiver — Two Forms of Nonideal LBM Forcing
·6 min read
Pressure-form and chemical-potential forcing agree for van der Waals in the continuum, then split on the lattice where the Gibbs-Duhem defect lives.
Where the Ideal Gas Starts to Lie — Compressibility Factor Z and the van der Waals Equation
·6 min read
Nitrogen at 100 bar and 200 K has Z = 0.7905. The ideal-gas density, 168.4 kg/m3, is about 26 percent lighter than the real 213.0.