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
Where Negative Density Leaks In — A Positivity-Preserving Flux Limiter for Blast Waves
·5 min read
The one-line θ-blend that keeps ρ above zero in a Le Blanc shock tube.
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