[Paper Review] The Capillary Shackle Came Off and CFL 0.05 Was Still There — The Real Ceiling on VOF Interface Advection
·9 min read
Implicit surface tension breaks the capillary time-step limit, yet the compressive scheme carrying the color function caps the time step at CFL 0.05.
When FTCS Trembles, Upwind Goes Numb — First-Order Advection, Artificial Viscosity, and the CFL Trade
·4 min read
At c=0.8 the worst FTCS mode grows by about 1.28 each step. Upwind artificial viscosity drops to zero only when c equals 1.