Mass Is Conserved Exactly, Yet the Density Is Negative — The Positivity-Preserving Flux Limiter
·8 min read
Bridging a high-order flux and the Lax–Friedrichs flux with a single θ per face
The Mach Number Goes to Zero, the Time Step Doesn't Budge — Reproducing an IMEX TVD Scheme
·10 min read
A second-order IMEX scheme that escapes the acoustic CFL without oscillating
When Lax–Wendroff Shook at a Step — Building a 2nd-Order TVD Advection Scheme with Flux Limiters
·5 min read
Sidestep Godunov's theorem to build a monotone 2nd-order advection scheme