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A computer model has been developed to predict diesel engine particulate emission during transients in speed and torque. The computer model consists of a quasi-steady-state engine combustion model, a dynamic engine model, and a dynamic turbocharger model. The model uses information developed from steady-state tests to predict the transient particulate emissions. The computer model accurately predicts engine airflow rate, turbocharger speed, and instantaneous engine equivalence ratio. The fuel consumption given by the model is within 3% of the experimental measurement over the EPA transient cycle. The brake-specific particulate emission during the transient cycle is also accurately predicted by the model. The predicted particulate emission is within 5% of the averaged experimental data over the EPA transient cycle.

The effects of ethanol fumigation on the performance and emissions of a four-cylinder, turbocharged diesel engine have been investigated. The effects of speed, load, alcohol proof, and the fraction of the engine's power supplied by the alcohol are presented. Comparisons are made with methanol and water injection. Analysis of the results shows that methanol and ethanol have almost identical effects when compared on an equal energy basis that includes the enthalpy of vaporization of the alcohol and water. The indicated thermal efficiencies of the alcohol and diesel fuel are separated, showing that the alcohol utilization is not affected by proof or fraction of power contributed by alcohol. A dramatic reduction in NOx emission suggests that fumigation may have potential as an emission control technique in diesel engines. A stoichiometric, adiabatic flame temperature is calculated and used to determine the contribution of lower combustion temperature to the decrease in NOx emission.