oa Spray characterization of gas-to-liquid alternative aviation fuels

Increase in energy demand and stringent emission standards drive the need for clean, alternative fuels. Gas-to-liquids (GTL), a liquid synthetic paraffinic kerosene (SPK) fuel obtained by Fischer-Tropsch synthesis has drawn global attention as an alternative aviation fuel due to its clean combustion characteristics when compared to conventional jet fuel. However, alternative fuels are expected to fulfill the key requirements such as having a quick atomization and vaporization and combustion and emission characteristics; similar to that of conventional fuels in order to qualify as a drop-in fuel in current aviation gas turbine engines. It is important to understand the atomization of these alternative fuels to better understand their combustion and emission characteristics. The key objective of this work is to evaluate the atomization characteristics of GTL-SPK which could potentially be used as a drop-in fuel in aircraft gas turbine engines in future. This work will discuss in detail the experimental facility developed, methodology and the results obtained using two GTL-SPKs having different chemical compositions. The spray characteristics such as droplet size and distribution are studied at three injection pressures using a pressure nozzle and compared to that of conventional Jet A-1 fuel. Results obtained clearly show that despite a considerable change in chemical composition, which in turn modestly altered the fluid properties among SPKs, the change in spray characteristics are found to be insignificant. This could be due to the minimal difference in fluid properties between the GTL-SPKs. In addition, the spray characteristics of the GTL-SPKs show close similarity to the spray characteristics of Jet A-1 fuel.