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A super-microcomputer is utilized in an engine-dynamometer facility to create a comprehensive engine evaluation system. A unique feature of this system is the combination of experimental and modelling activities in evaluating engine designs. The system acquires engine operating conditions, emissions, and dynamic cylinder and manifold pressures via the data acquisition interface. After acquisition, the computer is also capable of providing engine model predictions from either an empirical model or a zero-dimensional thermodynamic model. The data gathering process is speed limited by the settling time of the engine-dynamometer system. The acquisition and modelling procedures are controlled by an internally developed, menu driven, software package. Features of the system include commercial relational database software for rapid storage and retrieval of acquired data and a high resolution graphics monitor for immediate display of analyzed pressure data.

The direct injection gasoline spray-wall interaction was characterized inside a heated pressurized chamber using various visualization techniques, including high-speed laser-sheet macroscopic and microscopic movies up to 25,000 frames per second, shadowgraph, and doublespark particle image velocimetry. Two hollow cone high-pressure swirl injectors having different cone angles were used to inject gasoline onto a heated plate at two different impingement angles. Based on the visualization results, the overall transient spray impingement structure, fuel film formation, and preliminary droplet size and velocity were analyzed. The results show that upward spray vortex inside the spray is more obvious at elevated temperature condition, particularly for the wide-cone-angle injector, due to the vaporization of small droplets and decreased air density. Film build-up on the surface is clearly observed at both ambient and elevated temperature, especially for narrow cone spray.