The transient force profile of low-speed droplet impact: Measurements and model

Abstract

The transient force exerted by a low-speed liquid droplet impinging onto a flat rigid surface is investigated experimentally. The measurements employ a high-sensitivity piezo-electric sensor, along with a high-speed camera, and cover four decades in droplet Reynolds number and greater than two decades in Weber number. Across these ranges, the peak of individual force profiles span from 3 mN to over 1300 mN. Once normalised, the force-time profiles support the existence of an inertially dominated self-similar regime. Within this regime, previous numerical and theoretical studies predict a √t dependence of impact normal force during the initial pre-peak rise. While our measurements confirm thi..