Study on Dynamic Characteristics of Single Droplet Impingement on Heated Liquid Film

• DOI: 10.4209/aaqr.220366
• Publication Date: 2023-01-06T09:37:55Z
• Authors: Han Wu; Cong Liu; Chunze Cen; Chien-Er Huang; Sheng-Lun Lin
• Keywords: Dimensionless quantity; Deposition; Weber number

The wall combustion is one of the soot and unburned hydrocarbon formation sources in engine cylinders, which affected by both spray parameters. impingement dynamics droplets on liquid films have been widely studied. However, there less focus droplet impingements hot film, more representative as a pre-wall condition. This work investigates ethanol heated glycerol film. Weber number (10 ≤ We 275) film temperature (70°C T 175°C) are two main parameters that lead to comprehensive understanding impinging phenomena. In experiment, high-speed camera was used visualize behaviors, could be classified six categories: deposition-spreading, rebounding-sputtering, rebounding-floating, stable crown-spreading, crown-sputtering, splash crown-sputtering. critical for sputtering about 125°C, independent We. dynamic phenomena were quantified diameter height crown, time size distribution. dimensionless diameter, height, maintenance crown all increase with increasing or temperature. When greater than 172, increases less. relationship between maximum H*max = 0.0026 change from Additionally, decreases For distribution droplets, fractions larger increased at low We, while smaller their contributions high With temperature, proportion small increases.