High Pressure Fuel Injected Stoichiometric Engine System

Two major objectives of the U.S. Army is to increase power density and reduce heat rejection. Reducing airflow requirements of the deisel engine will contribute toward both of these objectives. Reducing air-fuel ratio requirements is one of the major cost effective approaches available for significantly increasing power output and reducing heat rejection in today's power output diesel engine. Power output of a diesel engine is determined by the amount of fuel injected which is limited by engine air utilization efficiency and system airflow capabilities. The diesel engine uses excess airflow to overcome the reduced air utilization performance characteristics of the conventional fuel injection system. The traditional diesel uses nearly twice the airflow theoretically required. This excess airflow limits the maximum possible power output rating and performance as a result of increased cylinder pressure and increased aftercooling heat rejection. Maximum allowable cylinder pressures are limited by structural and bearing durability considerations. The traditional excess airflow requirements can be overcome through the use of high pressure fuel injection to improve air utilization. High fuel injection pressures have been used to improve combustion efficiences at traditioanl high airflows and can be extended for increasing power output and reducing airflow requirements.