The concept of direct-injection spark-ignited engines is attractive for many reasons, but the literature has shown that implementation of the concept is difficult. Specifically, the performance and emission of these types of engines have been shown to be extremely sensitive to engine operating conditions. A thorough understanding of the interaction between the fuel spray and in-cylinder gas flow is required for successful implementation of this engine concept. To this end, the primary objective of this dissertation was to investigate the in-cylinder interaction in a motored direct-injection spark-ignited engine.
The methodology of this investigation involved two steps. First, the performance of a candidate fuel injector was characterized outside of an engine. Next, the injector was characterized inside an engine and the results were compared to those obtained out-of-cylinder. Three representative loads, injection pressures, and injection timings were examined.