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Air drag
Nozzle, drops and wind
Model checks
The science
Exit speed and ballistics
Bernoulli's equation for the nozzle gives v = Cv √(2 Δp / ρ) (Cv about 0.97 for a smooth nozzle), so 1 bar drives water out at about 14 m/s. In vacuum every droplet then follows a parabola with maximum height v²/(2g) and range v² sin(2θ)/g.
Air drag
A droplet of diameter d feels F = ½ ρair Cd(Re) A |v - uwind|(v - uwind) with Re = ρair |v| d / μair and the standard sphere correlation Cd = 24/Re (1 + 0.15 Re0.687) up to Re = 1000. Small drops lose most of their height and are blown away by wind; large drops fall almost freely. The terminal speed solves m g = ½ ρ Cd A v².
Honest simplifications: a 2D plane (no swirl), drops are rigid spheres (no break-up, coalescence, evaporation or oscillation), the nozzle is a single orifice with fixed discharge coefficient, the wind is uniform, the jet is not slowed by entrained air, and the drops are drawn larger than their true size so they stay visible.
What to try
- Switch air drag off and on: the vacuum height v²/2g (dashed line) is never reached by real drops.
- Press Fine mist and then Wide spray to compare small and large drops.
- Apply a side wind and watch the landing histogram shift.