Microscopic spray measurements of non-reacting alternative jet fuel: Effect of ambient gas temperature

Abstract

The volatile characteristics of alternative Gas-to-Liquid (GTL) jet fuel and conventional Jet A-1 fuel are significantly different due to their chemical composition variations. This difference can have a strong influence on the atomization performance at elevated ambient gas temperature conditions. Because the atomization process plays a vital role in fuel distribution inside the combustor, which ultimately affects heat release and emission patterns. The objective of the present work is to investigate the effects of ambient gas temperature and nozzle pressure differential on the non-reacting, microscopic spray performance of the alternative jet fuel using a pressure-swirl nozzle, and then, compare these effects to those of Jet A-1 fuel. Specifically, this study investigates the droplet size, velocity and distribution, by employing the Phase Doppler Anemometry technique to measure these parameters at several radial and axial locations downstream of the nozzle exit. The effect of ambient gas temperatures is studied at 300, 350, and 400 K at two nozzle pressure differentials, 300 and 900 kPa, while maintaining a constant ambient gas pressure and fuel temperature. Results show that, in the region investigated, there is a significant difference between the spray performances of GTL and Jet A-1 at elevated operating conditions. The outcomes of this study will add new knowledge to the limited scientific literature on the effect of ambient gas conditions on the local spray parameters of alternative jet fuel.