Engineers at Southwest Research Institute (SwRI) have developed a reliable testing methodology to study stochastic pre-ignition (SPI) in hydrogen-fueled internal combustion engines (H2-ICEs), offering the automotive industry tools to address challenges associated with hydrogen fuel and advance cleaner engine technologies.
Pre-ignition, where unintentional combustion occurs before spark timing, is disruptive and sometimes detrimental to engine performance and durability. While hydrogen's low ignition threshold is a suspected SPI factor, SwRI explored whether lubricant autoignition contributes to SPI in H2-ICEs.
Dr. Vickey Kalaskar, lead engineer with SwRI’s Powertrain Systems Engineering Department, said, “H2-ICEs experience pre-ignition at higher frequencies than spark-ignited gasoline engines, although the events are milder compared to the intense SPI events observed in SI gasoline ICEs, which can cause severe mechanical damage. The research conducted demonstrates that while additive chemistry appears to be the dominant driver for gasoline engine SPI, lubricant oil volatility and compression ratio are driving influences for hydrogen-fueled pre-ignition events.”
Through the course of this research, SwRI engineers developed a new testing methodology, which provides insight into lubricant-initiated SPI in H2-ICEs and supports further work, such as refining SPI quantification methods, exploring mitigation strategies and evaluating commercial lubricants.
