High-temperature ignition behavior of conventional and GTL fuels using an aerosol shock tube

Abstract

Ignition-delay-time measurements of conventional and a GTL liquid fuel have been recorded in a new aerosol shock tube. While the facility can be used for investigating both gaseous and condensed-phase mixtures, it was used in the present study to generate aerosolized fuel-air mixtures and study their ignition behavior. The fuels investigated were two conventional fuels commonly used in the transportation industry, Jet-A and DF-2, along with a GTL diesel fuel produced from the Fisher-Tropsch process. A brief overview of the functions of the new facility is provided, along with all measured ignition delay time data. The importance of careful experimental considerations when operating an aerosol shock tube cannot be overemphasized, and the challenges associated with using such facilities for quality chemical kinetics measurements are highlighted in detail. The temperatures and pressures at which the various fuels were studied ranged from approximately 950 to 1250 K and 5 to 10 atm, respectively, at two equivalence ratios of 0.5 and 1.0. Ignition delay time data were recorded using endwall emission diagnostics for measuring broadband and CH* (~431 nm) emission profiles and were compared to ignition delay time data from the literature. Good agreement was also seen between the new results from the aerosol shock tube when compared to available data for Jet-A and DF-2 for the same fuel batches and at similar conditions, but obtained using a heated shock tube. To our knowledge, the GTL diesel fuel ignition data presented herein are the first of their kind recorded in either a heated shock tube or an aerosol shock tube, further demonstrating the unique capabilities of the facility.