“Turbulence is the most important unsolved problem of classical physics.”
Field notes from a compressible multiphase CFD researcher
Top posts this week
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Implicit Diffusion and the Thomas Algorithm — Buying Stability with One Tridiagonal Solvenew
Past the explicit blow-up wall, the cost of unconditional stability is one O(N) sweep
[Paper Review] When the Sound Speed Diverges and the Time Step Survives — Orlando–Bonaventura (2024) AP-IMEX for Non-Ideal Gasesnew
An AP-IMEX-DG scheme that frees the time step from the sound speed across all Mach numbers and any EOS, reproduced in NumPy.
[Paper Review] Pick the Reconstruction with Smaller Jumps — Deng (2018) MUSCL-THINC-BVDnewnumerical-methods
Choosing between two candidate reconstructions by minimizing total boundary variation
When Characteristics Collide, a Shock Is Born — Burgers and the (x,t) Planenew
How nonlinear self-advection breaks a smooth curve into a shock.
Water Boils at 20°C Too — The Physics of Cavitationnew
How depressurization makes water boil, the cavitation number, and the 10,000-bar collapse.
SPH Without Tears — Solving Fluids with Particles, from Kernel to Artificial Viscositynew
How Smoothed Particle Hydrodynamics replaces grids with particles — equations, code, traps.
Two Faces of a Whirl — Free Vortex, Forced Vortex, and Helmholtznew
From a bathtub drain to a tornado, what vorticity actually measures
Quadtree AMR — Letting the Mesh Grow Where It Needs Tonew
Forty years of adaptive mesh data structures and refinement criteria, since Berger–Oliger
[Paper Review] Beating the Storm Clock — Casulli–Walters (2000) Semi-Implicit Shallow Water on Unstructured Orthogonal Gridsnumerical-methods
A shallow-water algorithm that stays stable at large time steps
[Paper Review] When WENO Smears Small Eddies — Fu (2019) Low-Dissipation TENO Finite-Volume Schemenumerical-methods
Why 5th-order WENO-JS still smears smooth scales, and how TENO's sharp cutoff fixes it
When Lax–Wendroff Shook at a Step — Building a 2nd-Order TVD Advection Scheme with Flux Limitersnumerical-methods
Sidestep Godunov's theorem to build a monotone 2nd-order advection scheme
Why Water Streams Break into Droplets — Plateau–Rayleigh Instability and Breakup Regimes
The principle of surface tension fragmenting liquid jets into droplets and the dimensionless map of spray design.