Experimental studies on the unsteady atomization characteristics of a swirl injector

This paper studies the spray and dynamic respond characteristics of a swirl injector under the different unsteady experimental conditions. The flow pulsation and injector geometric parameters, such as the pulsation frequency and swirl chamber length, on the atomization features like average liquid sheet thickness and spray angle have been comprehensively measured. It is indicated that the whole pulsation range could be divided into different parts based on the pulsation frequencies of incoming flow. Experimental results reveal that the liquid sheet thickness and Sauter Mean Diameter (SMD) amplitude would decrease in the square and bimodal regions and then remain unchanged in the triangular region. Both of them would increase with the tangential channel diameter and swirl chamber length while the steady incoming pressure drop shows an opposite impact on them. Besides, the spray performance of swirl injector could be improved by rising the swirl chamber diameter.