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The present study is the result of 4 years experimental research study aimed at understanding the hydrodynamic and heat transfer phenomena of a Diesel fuel droplet during the impact process with a heated flat and spherical surface. Such a phenomena are of a direct relevance to many engineering problems such as IC engines and fluid catalytic cracking (FCC). Due to the fact that the spray systems in the aforementioned applications may be comprised of millions of interacting droplets that prohibit detailed identification of the flow conditions during the impact of individual droplets, the current study focus on the characterisation of the impact dynamics of single droplets under well-controlled conditions. Several parameters, such as droplet velocity and diameter, liquid physical properties, surface conditions and geometry, wall surface temperature and ambient pressure are of key importance for the deformation of droplets upon impact and thus, define the impact outcome. An experimental investigation of micrometric Diesel droplets impacting on a heated aluminium and a millimetric brass particle surface was carried out. Dual view high-speed imaging has been employed to visualise the evolution of the impact process at various conditions. The parameters investigated include wall surface temperature ranging from room temperature to above Leidenfrost temperature (~420°C), impact Weber, and Reynolds numbers and ambient pressure of 1 and 2 bar. The observed post-impact outcome regimes are defined by means of hydrodynamic regimes and droplet morphology (stick, splash, break-up and rebound); then for each surface geometry, the …