A numerical study of multi-component droplets thermally-induced secondary atomization at high pressure

Thermally-induced secondary atomization is a complex phenomenon that can improve phase change in the combustion chamber. Pressure plays a significant role in the intensity and characteristics of the atomization process. Fragmentation is significant when processing blends of fuel with different volatilities, which is the case of a mixture of fossil and bio-derived fuels. A CFD model was developed to overcome the limitation of experiments in observing such a multi-scale phenomenon. The model is based on the Volume of Fluid methodology, which accurately tracks the evolution of the liquid-gas interface in time, thus identifying the formation of liquid structure and precisely estimating boiling. The algorithm was validated against analytical cases and experimental data prior to being tested with a hypothetical scenario of a droplet under pressure suddenly exposed to a hot environment at 1200 °C. The two mechanisms of atomization at 1 and 5 bar were then compared prior to concluding with significant observations and future expected developments.