Progress on spray autoignition under the extreme conditions in aero-engines

The lean premixed prevaporized (LPP) combustion is the most advanced low emission combustion technology of civil aero-engines. However, the LPP technology faces the risks of autoignition and flashback during the premixing process, which becomes the bottle-neck restricting the development of LPP technology. Under the extreme inlet conditions of high temperature (up to 1000K) and high pressure (up to 6MPa) in the aero-engine combustor, the autoignition in premixed and prevaporised section is a liquid fuel spray autoignition process in confinement. This paper reviews and analyzes the experimental research on the spray autoignition. Firstly, the spray autoignition process in the LPP combustor of civil aero-engine is described, the influencing factors and characteristics of spray autoignition are analyzed, and the key research directions are pointed out. Secondly, the study on the chemical autoignition is briefly reviewed and the effects of parameters on chemical autoignition are summarized. Finally, the experimental research status of spray autoigniton is analyzed, the research progress of autoigniton randomness under the extreme conditions in aero-engines is demonstrated, and the issues and subsequent developments are discussed.