Scuderi Split Cycle Engine: Air Hybrid Vehicle Powertrain Simulation Study 2012-01-1013

The Scuderi engine is a split cycle design that divides the four strokes of a conventional combustion cycle over two paired cylinders, one intake/compression cylinder and one power/exhaust cylinder, connected by a crossover port. This configuration provides potential benefits to the combustion process, as well as presenting some challenges; it also creates the possibility for pneumatic hybridization of the engine. This paper presents the methodology and results of a comprehensive study to investigate the benefits of air hybrid operation with the Scuderi Split Cycle (SSC) engine.

Four air hybrid operating modes are made possible by the Split Cycle configuration, namely air compressor, air expander, air expander & firing and firing & charging. The predicted operating requirements for each individual operating mode are established. The air and fuel flow of the individual modes are fully mapped throughout the engine operating speed and load range and air tank pressure operating range.

With the requirements for engine speed and torque derived from a specified drive cycle, the optimum hybrid operating mode at each point is selected to minimize the overall drive cycle fuel consumption. The influence of air storage tank insulation on the vehicle fuel economy is briefly studied. The resulting fuel consumption is compared with that from a non-hybrid SSC powered vehicle to demonstrate the benefits of the pneumatic hybrid architecture.