Study on the wall-guided stratified lean combustion of methanol flash-boiling spray

Abstract This study explores the characteristics of wall-guided stratified lean combustion of methanol flash boiling spray using a combustion chamber. High-speed imaging is employed to record the spray and flame development processes, focusing on the formation of fuel-rich regions around the ignition electrodes, flame kernel growth, and yellow sooting flame distribution. The results indicate that, compared to n-heptane, methanol stratified combustion features orange flame and a broader distribution of yellow flame regions. Under flash boiling conditions, the methanol spray collapses into a single jet, with a concentrated target region on the spray guiding plate. Furthermore, flash-boiling methanol stratified combustion exhibits a 150 % increase in flame kernel development speed and faster flame propagation compared to methanol subcooled stratified combustion, with soot formation primarily at the spray collapse region.