An Improved Method of Determining the TDC Position in a PV-Diagram

The characteristics of four major types of errors in PV-diagrams, ie. pegged basic pressure, clearance volume, TDC crank angle position and gas leakage from the cylinder, and their effect on the polytropic index are examined. An equation was proposed for each of those errors in a previous study. In this study an attempt is made to calculate the value of each of these deviations from measured data, using the characteristics of the polytropic indices and statistical method.