Technical Paper
The Comparison of Mass Fraction Burned Obtained from the Cylinder Pressure Signal and Spark Plug Ion Signal
1998-02-23
980140
This paper focuses on comparing the mass fraction burned obtained by pressure sensing and ion sensing through a conventional spark plug. The mass fraction burned curves obtained from both methods at different engine operating conditions are compared. In addition, the 0-10%; 50%, and 90% mass fraction burn durations are also compared. Traditionally, the mass fraction burned for a spark ignition engine is obtained through the measurement of pressure signal and the well known Rassweiler-Withrow method, which requires an expensive pressure sensor and some rather complex instrumentation. Ion sensing through a spark plug is very cost effective and reveals much information about the combustion process in the cylinder. Instead of making assumptions to attain the mass fraction burned, ion sensing by a spark plug allows us to obtain the mass fraction burned information through the Wiebe function constructed by several critical events shown in the ion signal during the combustion.