Divided-Chamber Diesel Engine, Part II: Experimental Validation of a Predictive Cycle-Simulation and Heat Release Analysis

In this study, a set of performance and emissions data, obtained from a single-cylinder divided-chamber automotive diesel engine over the normal engine operating range, is described and analyzed. The data are used to evaluate a computer simulation of the engine's operating cycle, described in a companion paper, which predicts the properties of gases inside the engine cylinder throughout the cycle, and engine efficiency, power and NO_x emissions. Satisfactory agreement between predictions and measurements is obtained over most of the engine's operating range.

The characteristics of the experimental pre- and main-chamber pressure versus crank angle data are then examined in detail. A heat release analysis appropriate for divided-chamber diesel engines is developed and used to obtain heat release rate profiles through the combustion process. A useful method for estimating the heat transfer during combustion from the heat release profile and the heating value of the injected fuel is developed and applied to this data base.