Exprimental Study of Atomization Feature of Coaxial Parallel Flow Airspray Nozzle

Plain orifice and direct injector nozzle are increasingly used in advanced combustion chamber. In order to reduce the sensitivity of the single-phase liquid jet to the changes of air flow, another air jet can be added to form a air-liquid two-phase flow. In this paper, the atomization characteristics of the air-liquid two-phase jet during cross-airflow jetting are experimentally studied with optical instruments. The structure of the two-phase flow is to wrap a layer of annular air jet outside the liquid jet. Experiments show that when the mass flow rates of the annular air and liquid jets are relatively large, the jets will bifurcate and the droplet size will also be significantly different. When the air-liquid ratio continues to increase, the atomization-assisting effect of the annular air will also increase, and the droplet size difference will also decrease.