At acoustic CFL 10 the preconditioner multiplied the error by 100 every sweep — the one arrow a block preconditioner throws away
·8 min read
Block Gauss-Seidel discards a pressure-velocity feedback whose gain is exactly the acoustic CFL squared. A 1D acoustic model measures the cost.
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
Letting Sound and Matter Flow Separately — Acoustic-Convective Splitting (Lagrange-Projection)
·5 min read
Implementing the Lagrange-Projection scheme that sidesteps low-Mach stiffness by splitting acoustics from convection
[Paper Review] Not Killing Sound at Low Mach — An AP IMEX Wave Scheme
·5 min read
Why upwind viscosity erases the solution at low Mach, and the AP-IMEX cure
[Paper Review] Stop letting sound speed swallow your CFL — Peluchon (2017) acoustic-transport IMEX
·6 min read
Splitting acoustic from transport gives a 1/M time-step gain on the five-equation model
[Paper Review] Why Roe breaks at low Mach — Hope–Collins (2022) and three artificial-diffusion scalings
·6 min read
How a standard Roe flux collapses at M=0.01, and the three scalings the asymptotics prescribe.
[Paper Review] When the Sound Speed Diverges and the Time Step Survives — Orlando–Bonaventura (2024) AP-IMEX for Non-Ideal Gases
·6 min read
An AP-IMEX-DG scheme that frees the time step from the sound speed across all Mach numbers and any EOS, reproduced in NumPy.