Influence of Fuel Composition on the Operation of a Liquid Fueled Resonant Pulse Combustor

In this study, the response of a liquid-fueled resonant pulse combustor to changes in fuel composition was investigated. Experiments were performed with gasoline-diesel and gasolineethanol mixtures selected to produce a meaningful variation in the ignition delay time. Through a review of ignition quality test (IQT) data, it was expected that the overall ignition delay time would increase for gasoline-ethanol mixtures relative to gasoline, and decrease for gasolinediesel mixtures. Using the phase of peak pressure as a proxy to mark variation in heat release timing, the experimental results displayed an agreement with the IQT data with a near linear increase with decreasing gasoline concentration. However, for the case of gasolinediesel, there exists no linear relation with the IQT data. Furthermore, it was shown that small changes in ignition delay can significantly alter the coupling between the unsteady heat release and resonant acoustic pressure wave and thus the performance of the combustor. Dynamic combustion chamber pressure, stagnation temperature and pressure are recorded after a fixed warm-up time to characterize the performance and operation of the device. Results are interpreted in the context of fuel sensitivity and performance optimization of resonant pulse combustor for pressure gain turbine applications.