The objective of this study is to determine the ignition feasibility of a single shot, air-assisted gasoline fuel injector operated in a constant volume combustion chamber under atmospheric condition. A number of parameters has been selected for this experiments, such as dwelling time, spark gap position(r, z), spark electrode geometry, supplied air and fuel masses and spray cone deflector.
On-site visual inspection of the instantaneous flame glow was chosen as one way to judge the successful ignition. In addition, chamber pressure and occasional photography were mobilized for data recording. It was clearly observed that there was an entrainment air-fuel mixture toward spray axis from the spray formation and its development later on. It was noticed that region along stream axis is the most favorable area for successful ignition which could be partial explainable by the local mixture entrainment. In order for a successful ignition, a maximum limit in air mass flow existed for a given amount of fuel. The optimum ignition condition was formed only after a short time later the passage of injected spray front. The spark electrode geometry was an important factor in satisfying ignition in an air-assisted injector. A sharp angled deflector was necessary for ignition at light load condition.