One Integral Read as 0.1406 and 56.91 — Torsion Stress Function and Duct Laminar Flow
·8 min read
A square bar's torsion constant and a square duct's f·Re are one Poisson solution read twice. One linear-triangle FEM run gives both handbook numbers.
What Jacobi Cannot Kill in 10,000 Sweeps, a V-Cycle Kills in 10 — The Real Secret of Multigrid
·6 min read
Swap the grid, swap the frequency: how a hierarchy converts stubborn low modes into easy ones