(2-17) Studies of Temperature Elevation Due to the Pre-Flame Reaction in a Spark-Ignition Engine with CARS Temperature Measurements Using Fuels of Various Octane Numbers((SI-5)S. I. Engine Combustion 5-In-Cylinder A/F and Temperatures)

概要

論文の詳細を見る
The unburned end-gas temperatures in a combustion chamber of a conventional 4-cylinder DOHC spark-ignition engine were measured using the broadband CARS temperature measurement technique. The test engine was fueled with primary reference fuel 80 and fuels with research octane numbers of 70.9, 83.4, 91.5 and 100.4. The measured CARS temperatures were compared with adiabatic core temperatures calculated from measured pressures. Significant heating by pre-flame reaction in the end gas zone was observed in the late part of compression stroke under both knocking and non-knocking conditions. CARS temperatures measured at the cylinder pressure of 1400 kPa and above were higher than adiabatic core temperatures. These results indicate that some exothermic reactions exist in low pressure and temperature regions. The CARS temperatures began to be higher than the adiabatic core temperature when the end-gas temperatures reached 700 K. The temperature elevation due to the pre-flame reaction correlated better with the CARS temperature than with the cylinder pressure. The temperature elevation showed very good correlation with the unburned gas temperature without regard to the research octane number of fuel.
一般社団法人日本機械学会の論文
2001-07-01