2016

Ignition studies of n-heptane/iso-octane/toluene blends

Ignition studies of n-heptane/iso-octane/toluene blends


​T. Javed, C. Lee, M. AlAbbad, K. Djebbi, M. Beshir, J. Badra, H. Curran, A. Farooq
Combustion and Flame 171, 223-233, (2016)​

T. Javed, C. Lee, M. AlAbbad, K. Djebbi, M. Beshir, J. Badra, H. Curran, A. Farooq
TPRF surrogates; RON; MON; Ignition delay times; Shock tubes; RCMs
2016


​Ignition delay times of four ternary blends of n-heptane/iso-octane/toluene, referred to as Toluene Primary Reference Fuels (TPRFs), have been measured in a high-pressure shock tube and in a rapid compression machine. The TPRFs were formulated to match the research octane number (RON) and motor octane number (MON) of two high-octane gasolines and two prospective low-octane naphtha fuels. The experiments were carried out over a wide range of temperatures (650–1250 K), at pressures of 10, 20 and 40 bar, and at equivalence ratios of 0.5 and 1.0. It was observed that the ignition delay times of these TPRFs exhibit negligible octane dependence at high temperatures (T > 1000 K), weak octane dependence at low temperatures (T < 700 K), and strong octane dependence in the negative temperature coefficient (NTC) regime. A detailed chemical kinetic model was used to simulate and interpret the measured data. It was shown that the kinetic model requires general improvements to better predict low-temperature conditions and particularly requires improvements for high sensitivity (high toluene concentration) TPRF blends. These datasets will serve as important benchmark for future gasoline surrogate mechanism development and validation.