Barrel Explosion — Blast Overpressure & Fragment Scatter (2D)

This is a 2D-native companion to the 3D explosive-barrel simulator. Instead of a clickable field of barrels with a scripted fixed-radius chain reaction, it solves the actual empirical blast-scaling relations used in explosive-safety engineering — Hopkinson-Cranz cube-root scaling, the Kingery-Bulmash peak-overpressure curve fit, and the Gurney equation for fragment ejection velocity — for a single barrel of chosen TNT-equivalent charge mass. A top-down panel animates the decelerating shock ring (Sedov-Taylor R∝t^(2/5) scaling) and shrapnel scatter, while a log-log chart plots peak overpressure against distance for the current charge and marks your chosen observer distance against standard hazard thresholds.