Empirical model for the maximum spreading diameter of low-viscosity droplets on a dry wall

While many studies have explored droplet impacts using water, glycerin, or a water-glycerin mixture, few studies have investigated droplet impacts using low-viscosity fluids, such as hydrocarbons, which are commonly used in the automobile and aerospace industries. In the present study, the maximum spreading diameter of gasoline, isooctane, and ethanol droplets on an aluminum substrate was investigated. An empirical model with an accuracy of 5% error was proposed. The working fluid viscosity range was 0.45 < μ < 1.29 mPa s, and the droplet impact velocity range was 0.37 < V < 4.04 m/s for a droplet diameter of 2.5 mm. The experimental ranges for the Reynolds number and the Weber number were 560 < Re < 15,000 and 12 < We < 1,600, respectively.