I Dropped the −1/2 and the Viscosity Came Back Six Times Too Large — the Δt/2 Left Behind by LBM's Discretisation
·6 min read
One trapezoidal integration and one change of variables leave a Δt/2 in three separate places: the viscosity, the velocity, and the stress. A scalar ODE and a D2Q9 lattice measure all three.
Viscosity Is Not What Kills a Vortex — Newton's 1/r and the Lamb–Oseen Core
·7 min read
A free vortex carries huge shear stress and still refuses to decay. The core and the wall hold the clock.
The Paramecium Swims Through Honey — Where Viscosity Comes From and Why Fourier and Fick Wrote the Same Line
·5 min read
Molecules carry momentum across an imaginary plane — and one identity ties viscosity, heat, and diffusion together