Spray dynamic collapse characteristics and mechanism induced by alcohol addition

As renewable fuel, alcohol could be added into the fuel with low volatility to trigger flash boiling, which has been considered an effective method to facilitate the atomization of fuel sprays and reduce emissions. However, the competing relationship between volatility and high latent heat leads to a complex atomization process, making it more challenging to investigate the effects of alcohol addition on plume interaction and vortex evolution. To illustrate the influences of alcohol addition on the fuel atomization performance, spray macroscopic and microscopic characteristics under various operating conditions were obtained using Diffuse Backlight Illumination (DBI) and Phase Doppler Anemometry (PDA) methods, and dynamic collapse ratio were used to characterize morphologies variations. The addition of alcohol facilitates the nucleation process, and its effects are affected by heavy components, attributed to the dependence of the energy barrier of nucleation on fuel properties. Parameters were proposed based on the energy barrier, supplementing R p to predict the plume expansion of fuels with unknown properties. The dynamic collapse ratio is able to reflect the plume evaporation efficiency, plume interaction and vortex movement direction. This study aims to shed more light on the flashing characteristics of multi-component fuels with distinct properties, facilitating the efficient utilization of renewable fuels.