Advanced combustion in heavy fuel aircraft piston engines: A comprehensive review and future directions.

• Combustion systems and aviation adaptability in piston engines are analyzed. • The key technologies related to in-cylinder combustion research are summarized. • Combustion characteristics and aviation adaptability of fuels are examined. • Future development directions of combustion technology are analyzed and predicted. The in-cylinder combustion process is a focus on research on heavy fuel aviation piston engine (HF-APE), which is quite significant because of its strong correction with engine's power and economic performance, as well as the level of emissions. This study reviews the representative combustion types of HF-APE in recent years, and comprehensively analyzes their aviation adaptability from various aspects. A review was conducted from the perspective of visualization measurement, combustion analysis, and high-altitude simulation technologies, all of which are the crucial methods to study the HF-APE combustion process. A comparative study was investigated on the combustion characteristics and aviation adaptability under different fuels. To meet the requirements of airworthiness regulations and the development of general aviation for more energy saving and environmental protection, further summarizing the progress as well as predicting the trends of HF-APE combustion technologies, are expected to be promoted due to their valuable scientific significance and engineering applications. [ABSTRACT FROM AUTHOR]