An investigation into ignition and oxidation of RP-3 aviation kerosene under varied conditions − Part I: Experimental study

Data on the ignition delay times (IDTs) of aviation kerosene under high-pressure and low-temperature conditions remain scarce, primarily due to the characteristically low vapor pressures of multi-component fuels like RP-3 aviation kerosene. To address this challenge, a premixing-by-injection strategy was developed to facilitate reliable shock tube measurements of such low-volatility fuels. Auxiliary laser-absorption measurements were used to examine the temporal evolution of fuel/bath-gas mixing and showed that elevated initial temperature can substantially shorten the time required for the mixture signal to stabilize. Direct validation under the HPST conditions was then performed by comparing IDTs obtained with different residence times and with conventional premixing methods. High-temperature tests confirmed that a short residence time at 120 °C suffices to achieve a homogeneous mixture. The method was validated through benchmark experiments using n -heptane, iso -octane, and n -dodecane. The results showed excellent agreement with both conventional premixed data and kinetic simulations, and successfully captured the two-stage ignition behavior in the negative temperature coefficient (NTC) regime. Subsequently, the method was applied to RP-3 kerosene, yielding the first systematic IDT dataset for a fuel–air mixture under high-pressure, low-temperature conditions. These results provide critical targets for validating the kinetic model, demonstrate the robustness of the injection strategy for studying liquid fuels, and highlight the necessity of developing refined surrogate formulations to achieve predictive accuracy across a broad range of conditions.