Increasingly
stringent requirements for aerospace propulsion system
performance, reliability, and operability motivate quantitative connections
between fuel composition, physical characteristics, and system performance.
Chemically accurate assessment of aviation turbine fuels (Jet-A, JP-8,
etc.) and kerosene-based rocket propellants (RP-1 and RP-2) is requisite
to mature these models. Comprehensive two-dimensional gas chromatography
with time-of-flight mass spectrometry (GC × GC–TOFMS)
is an excellent analytical tool for measuring detailed chemical information
contained in complex fuels. Additionally, multivariate data analysis
methods, referred to as chemometrics, are ideally suited to relate
detailed chemical information contained within the GC × GC–TOFMS
data to fuel properties and performance in a predictive manner. Herein,
we apply these techniques to a chemically diverse set of 74 distillate
and multicomponent aerospace fuels, resulting in an improved understanding
of the chemical compositional basis for physical and thermochemical
behavior. Informed by GC × GC–TOFMS data, highly reliable
partial least squares (PLS) models are developed and employed in the
prediction of physical properties (measured separately using conventional
test methods). Root-mean-square errors of cross-validation (RMSECV)
were relatively low: values of 0.0450 cSt, 41.3 Btu/lbm, 0.130 mass
%, and 0.0064 g/mL were obtained for viscosity, heat of combustion,
hydrogen content, and density, respectively. The corresponding normalized
root-mean-square errors of cross-validation (NRMSECV) were 6.01, 10.3,
8.71, and 7.12%, respectively. Investigation of the linear regression
vectors (LRVs) provides valuable insight into the relationship between
the chemical composition and physical properties, enabling, in principle,
the model-informed selection of fuel chemical composition to achieve
desired performance criteria.