Integral characteristics of water droplet evaporation in high-temperature combustion products of typical flammable liquids using SP and IPI methods

Abstract

This paper examines the evaporation features of water droplets moving through high-temperature combustion products of typical flammable liquids (on an example of gasoline, kerosene, ethanol, and acetone). Using Shadow Photography and Interferometric Particle Imaging methods contributed to perform the given experimental research. Such approach enabled to establish the integral characteristics of droplet motion (sizes and velocities) and evaporation process (evaporation rate). The initial droplet sizes (radii) and the temperatures of combustion products varied in a wide range: 0.05–4 mm and 400–1900 K, respectively. The choice of these ranges allowed us to summarize the research results, which can be applied in a group of promising high-temperature (usually more than 1000 K) gas-vapor-droplet technologies (thermal or flame methods of liquid waste treatment; heat carriers based on flue gases, steam, and water droplets; polydisperse firefighting). Conditions of almost the complete and insignificant (with minimum change of liquid mass) droplet evaporation were determined. In addition, the integral characteristics of water droplet evaporation under non-stationary heat transfer (at a temperature of combustion products from 1900 K to 400 K) were compared with the same characteristics under nearly stationary heat transfer (at a temperature of 1100 ± 30 K). During short-time heating (less than 0.5 s), values of these parameters correlated well (deviations did not exceed 8–12%).