“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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Where Turbulence Stops Speeding Up a Flame — Damköhler's Wrinkling Hypothesis and Bending
The physics behind the three regimes of the turbulent flame speed curve: linear rise, bending, quenching
Where Half the Force Goes in LBM — Four Forcing Schemes and 1−1/(2τ)
Comparing lattice Boltzmann body-force schemes and pinning down the half-force correction
The Mach Number Goes to Zero, the Time Step Doesn't Budge — Reproducing an IMEX TVD Scheme
A second-order IMEX scheme that escapes the acoustic CFL without oscillating
Un-smearing the Interface Every Step — Implementing Anti-Diffusion Sharpening (IST)
A post-processing technique that pins a numerically smeared interface to a constant thickness
Supersonic Flow Can't See Upstream — Characteristics and Sound Waves in the Euler Equations
Why a small disturbance splits into three characteristic speeds
How Far Must Water Flow Before It Becomes a Parabola — Entrance Length and Hagen–Poiseuille
The pipe entrance region, the Hagen–Poiseuille parabola, and the 64/Re friction factor
When Pressure Rings in a Checkerboard — SIMPLE and Rhie-Chow Coupling
Why collocated pressure checkerboards, how Rhie-Chow fixes it, and the SIMPLE loop
A Single Ripple Outruns Its Own Group — Wave Dispersion and Group Velocity
Why every wavelength travels at its own speed, and phase and group part ways
In Lattice Boltzmann, the Wall Isn't on the Node — Bounce-Back and Zou-He Boundaries
The bounce rule that builds a no-slip wall, and where that wall really sits
Why a Droplet at Rest Starts to Flow — Parasitic Currents and Well-Balanced Surface Tension
The parasitic currents born from curvature error, and the well-balanced method that eliminates them
Deleting an Equation Made It More Robust — The Four-Equation Model and the Interface Equilibrium Condition
How the four-equation multiphase model kills interface pressure oscillations
When Gradients Go Wrong on Skewed Meshes — Green–Gauss vs. Weighted Least-Squares Reconstruction
Two ways to build cell gradients on unstructured meshes, and which one survives distortion