Experimental study on spray characteristics of aviation kerosene from a pressure-swirl nozzle in high-speed airflow with elevated temperatures

Abstract

Spray characteristics of aviation kerosene are critical to the performance of gas turbine combustors. Actual gas turbine combustors are mainly operated at high temperatures and high-speed airflow environments, whereas almost all research on spray characteristics in high-speed airflow is limited to room temperature in the literature. In this paper, the spray characteristics of aviation kerosene from a pressure-swirl nozzle are investigated experimentally in the airflow temperature range of 313–500 K and the airflow speed range of 108–136 m/s. The information on spray characteristics such as droplet flux, velocity, and diameter was obtained by phase Doppler anemometry. Planar Mie scatter was performed to obtain the information on the concentration distribution of spray. The results show that the droplet flux, velocity, concentration, and Sauter mean diameter (D32) change significantly with airflow temperatures. In special, D32 in the center recirculation zone shows an increasing trend with increasing airflow temperature. The difference in the change of D32 along the propagation direction at elevated airflow temperatures is mainly due to the difference in evaporation processes. It was found that the evaporation models of a droplet that existed in literature do not predict well the D32 variation of spray in this experiment. A new spray evaporation model considering turbulence and fuel vapor fraction is proposed, which significantly reduces the prediction errors of variation in D32 in this experiment. This paper can provide experimental data and preliminary theoretical references for subsequent investigation of spray characteristics in high-speed airflow with elevated temperatures.