This book focuses on developing strategies for ultra-lean combustion of natural gas and hydrogen, and contributes to the research on extending the lean flammability limit of hydrogen and air using a hot supersonic jet. The author addresses experimental methods, data analysis techniques, and results throughout each chapter and:
• Explains the fundamental mechanisms behind turbulent hot jet ignition using non-dimensional analysis
• Explores ignition characteristics by impinging hot jet and multiple jets in relation to better controllability and lean combustion
• Explores how different instability modes interact with the acoustic modes of the combustion chamber.
This book provides a potential answer to some of the issues that arise from lean engine operation, such as poor ignition, engine misfire, cycle-to-cycle variability, combustion instability, reduction in efficiency, and an increase in unburned hydrocarbon emissions. This thesis was submitted to and approved by Purdue University.