Synthetic\nBlend Component Study: The Effects of Hydrocarbon\nComposition on Aviation Fuel Dielectric Constant

The dielectric constant is used in aircraft for onboard\nfuel density\nand volume gauging, which is essential for safety and efficiency.\nThe goal of this paper is to report the effects of synthetic blend\ncomponents (SBCs)which have compositions that deviate from\nconventional Jet A fuelson density gauging. Dielectric constant\nand density measurements were taken using the newly developed Stanhope-Seta\nJetDC, which was designed to align with aircraft gauging equipment.\nMeasurements were taken for blends of SBCs with both Jet A and synthetic\naromatic kerosene (SAK), with a total of 269 observations generated\nfrom 0 to 40 °C. The gauging slope, which is the industry standard\nfor correlating dielectric constant with density, was calculated using\nthe measured values and compared to a distribution of 169 conventional\nfuels from the literature. It was found that the gauging slope varies\nsignificantly for SBCs, with values as low as 0.2946 for neat cycloparaffinic\nkerosene and as high as 0.4546 for neat SAK, relative to the average\nconventional fuel value of 0.3557. The dielectric constant data was\ncoupled with two-dimensional gas chromatography to explore the effect\nof fuel composition on gauging. Partial least-squares regression indicates\nthat alkylbenzenes and cycloaromatics have a positive correlation\nwith the gauging slope, while <i>iso</i>-alkanes, <i>n</i>-alkanes, and cycloalkanes have a negative correlation.\nDespite the influence of fuel composition on the gauging slope, it\nwas found that the resulting density errors were below the 1.2% threshold\nfor effective fuel gauging at the temperatures tested.