Computational and Experimental Investigation of the Density, Viscosity, and Surface Tension of Hydrocarbon–Oxygenated Fuel Blends at Low Temperatures

The use of oxygen-containing renewable components in aviation fuels requires reliable data on low-temperature properties, since density, viscosity, and surface tension have a significant effect on fuel atomization. In this study, these properties were experimentally determined, and correlations for their prediction were proposed for an aviation kerosene surrogate T/D (20 vol.% tetralin/80 vol.% n-decane) blended with isopropanol at subzero temperatures. The results were compared with those obtained for TS-1 jet fuel. Density was measured using a hydrometric method, viscosity by rotational viscometry, and surface tension by the du Noüy ring method. Empirical correlations and mixing rules were used for property prediction. The proposed surrogate reproduced the reference properties of TS-1 with deviations below 1% for most parameters, except for surface tension, which differed by 6.3% at 20 °C, and average molar mass, which differed by 3%. The predicted density agreed with the experimental data within 1%, whereas the average deviation was approximately 8% for viscosity and 4.5% for surface tension. These results indicate that the proposed equations are suitable for predicting the density, viscosity, and surface tension of oxygen-containing aviation fuels. The isopropanol-containing blend exhibited a higher viscosity than TS-1 at low temperatures and crystallized at −40 °C, which represents a limiting factor for the use of oxygenated additives in aviation fuels without additional pour-point-depressant additives.