Experimental investigation of the expansion characteristics of vaporized kerosene jets in a quiescent atmospheric environment

Abstract

In this paper, the time-averaged and instantaneous information of the vaporized kerosene jet injection into a quiescent atmospheric environment, including the expansion angle, deflection angle and shock wave structure, were acquired by natural light and a schlieren system. The results show that the jet expansion angle increases first and then decreases during the kerosene vaporization, which is mainly governed by the pressure change inside the shear layer and the variation in the jet axial speed. Compared with straight injection, the oblique scheme inhibits the jet expansion process and enhances the expansion property in the vertical and parallel directions of the bevel face. Because of the asymmetric configuration of the injector exit and the adsorptive effect of the bevel face, the jet plume in the oblique injection scheme obviously deflects along the axial direction. In addition, the expansion angle fluctuates when the vaporized kerosene is injected into some specific conditions. The frequency of the jet pulse is approximately 2.1 Hz, and the pulsation mode gradually converts during the vaporization process. The two-phase flow instability occurring in upstream heated kerosene might be responsible for this unique phenomenon.