Effect of Aromatics in Jet Fuels on Spray Characteristics Downstream of an Aeronautical Pressure Swirl Atomizer

Abstract

Standard aeronautic fuels have a lower limit of aromatics of 8% (by volume) with about 18% for regular Jet A1. It has been shown that aromatics contained in Jet fuel have an impact on the fine particle emissions. In order to reduce these emissions, alternative fuels with lower aromatic content have been identified as a promising solution. Change Jet fuel composition can have several effects on spray and combustion behaviors, among others: atomization process, droplet evaporation, flame structure, pollutant and particle emissions. Then, it is necessary to evaluate the impact of this change on gas turbine performance and operability. The present study is focused on the spray behavior investigation with different aromatic content. Four Jet fuels are investigated including conventional Jet A1 kerosene, drop-in fuel with a mixture of half conventional Jet fuel and synthetic paraffinic kerosene (SPK), SPK with 8% of aromatics and pure SPK. The tests are performed at atmospheric conditions on the MERCATO testbed located at ONERA (FR). Phase Doppler Anemometry (PDA) measurements are carried out for the four fuels on an injection system composed of a pressure swirl atomizer and an air swirler. In this paper, a spray analysis of liquid velocity and droplet diameter measurements is described and linked to the variations of fuel properties. In the range of parameters covered by the four different fuels, it is shown that the spray behavior of each fuel is similar to the conventional Jet A1.