1993-10-01

Prediction of the Performance of Spark Ignition Gas Engines Including Knock 932823

A two-zone predictive model for the performance of a spark ignited gas engine is described. In this model, an effective mass burning rate and energy release pattern based on an estimate of the combustion duration are developed. For any given engine and set of operating conditions the pressure-time and temperatures-time histories, and hence performance parameters such as indicated power output, peak pressure, optimum spark timing, etc. are predicted. Through monitoring the chemical reaction activity, while employing detailed chemical kinetics of the end gas within the unburnt zone, the incidence of autoignition and knock can also be predicted. A dimensionless knock criterion that compares the specific energy release due to end gas preignition reaction activity to the specific energy release due to combustion of the fuel is developed and used to test for the incidence of knock and its severity. The predicted performance appears to agree well with measured experimental behaviour when methane is the fuel.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.
X