Determining the Thermal Properties of Military Jet Fuel JP-5 and Surrogate Mixtures Using Differential Scanning Calorimetry/ Thermogravimetric Analysis and Differential Scanning Calorimetry Methods

摘要

Heat capacity and heat of vaporization (HoV) are thermal properties that affect the combustion of fuels in engines. This study highlights new calorimetric methods to measure the thermal properties of JP-5 and surrogate fuel systems. First, the heat capacities of military jet fuel (JP-5) and surrogate fuel mixtures were measured using a stand-alone differential scanning calorimeter. The surrogates consisted of two-component and four-component mixtures, which have been reported in past studies. Six quaternary and four binary mixtures had heat capacities matching those of JP-5 at 20 degrees C, 1.91 +/- 0.03 J.g(-1) degrees C, within a 90% confidence interval. The heats (energy) needed to evaporate JP-5 and each surrogate mixture were determined using a differential scanning calorimetry-thermogravimetric analysis system. Isothermal measurements were used to measure pure components. A temperature ramping protocol was designed for JP-5 and surrogate mixtures. The HoV of JP-5 was determined to be 239 +/- 8 J.g(-1), which falls within the range of literature values based on predictive correlations. The HoVs for six of the surrogate mixtures matched those of JP-5 within their 90% confidence intervals.