  Methyl valerate (C$_6$H$_{12}$O$_2$, methyl pentanoate) is a methyl ester and
a relevant surrogate component for biodiesel. In this work, we present ignition
delays of methyl valerate measured using a rapid compression machine at a range
of engine-relevant temperature, pressure, and equivalence ratio conditions. The
conditions we have studied include equivalence ratios from 0.25 to 2.0,
temperatures between 680 K and 1050 K, and pressures of 15 bar and 30 bar. The
ignition delay data demonstrate a negative temperature coefficient region in
the temperature range of 720 K-800 K for both $\phi$=2.0, 15 bar and
$\phi$=1.0, 30 bar, with two-stage ignition apparent over the narrower
temperature ranges of 720 K-760 K for the lower pressure and 740 K-800 K at the
higher pressure. In addition, the experimental ignition delay data are compared
with simulations using an existing chemical kinetic model from the literature.
The simulations with the literature model under-predict the data by factors
between 2 and 10 over the entire range of the experimental data. To help
determine the possible reasons for the discrepancy between simulations and
experiments, a new chemical kinetic model is developed using the Reaction
Mechanism Generator (RMG) software. The agreement between the experimental data
and the RMG model is improved but still not satisfactory. Directions for future
improvement of the methyl valerate model are discussed.
