Fluids & Combustion (real CFD)
Shear-Layer Vortex Roll
Kelvin–Helmholtz shear instability
Two opposing streams create a shear layer that rolls up into a vortex — the Kelvin–Helmholtz instability behind smoke rings and cloud billows.
Computed & rendered in pure C# on the frozen OnlyCSharp 1.8 library — animation baked to GIF with the library's own
Gif encoder (no GPU, no ffmpeg, no external packages).