Droplet Splash Simulator (2D)

Drop Setup

Drop height 0.5 m

Droplet diameter 3.0 mm

Liquid

Ready — release a droplet.

Live Readout

Impact speed

— m/s

Weber number

—

Reynolds number

—

Ohnesorge Oh

—

Regime

—

Crown droplets

—

How it works

A falling droplet hits terminal impact speed v = √(2gh) after falling from height h. Whether the impact produces a splashing crown or a calm deposition depends on the Weber number We = ρv²D/σ — the ratio of disruptive inertia to the surface tension holding the liquid together — and the Ohnesorge number Oh = μ/√(ρσD), which folds in viscosity.

Low We (gentle drop, small droplet, high surface tension) lets surface tension win: the droplet spreads into a smooth pancake and retracts — deposition, no splash. Once We climbs past roughly 40–100 (the exact threshold falls as Oh rises), inertia tears a thin sheet off the rim that fragments into flying secondary droplets — a crown splash, the same corona photographed by Harold Edgerton's high-speed strobe in the 1930s.

After the crown collapses, surface tension pulls the crater back in and overshoots into a central Rayleigh jet, which can pinch off its own droplet at the tip — visible here as the thin spike shooting up from the impact point. Try switching to glycerin: its high viscosity damps the crown almost completely, while alcohol's low surface tension splashes at heights water barely disturbs.