Project Number: 073
Category: Alternative Jet Fuels
In this study, the effect of fuel chemical composition on radiative heat transfer and the resulting combustor liner lifetime will be evaluated. Alternative jet fuels contain ratios of hydrocarbon types that differ from familiar petroleum-based fuels. For petroleum-based fuels, it is known that higher aromatics levels contribute to greater radiative heat transfer and reduced combustor liner lifetime. As a result, aromatics are limited to 25 volume percent in the ASTM D1655 jet fuel specification. Some candidate alternative jet fuels contain synthetically-produced aromatics and cycloparaffins, which need to be evaluated for their radiative heat transfer characteristics. The measurements will provide insight into the effect of fuel type on liner lifetime. Several fuel types will be investigated including a Synthetic Aromatic Kerosene, a baseline jet fuel, and a fuel that is high in cycloparaffins. Diagnostic methods to be used in the investigation include the measurement of wall and gas temperatures, infrared (IR) cameras, and radiometers. This funding will provide one year of support.
This study will quantify the potential benefits of changes in fuel composition to engine life. It will also ensure that future candidate fuels do not negatively impact the combustor liner lifetime of jet engines. As such, the study will ensure that candidate drop-in fuels will perform satisfactorily in jet engines and not increase engine maintenance nor decrease flight safety. A secondary benefit is that the measurements will be useful for the development of advanced, higher fidelity combustion models.