Brian Sangeorzan

ECU Development for a Formula SAE Engine

Motivated by experiences in the Formula SAE ® competition, an engine control unit (ECU) was designed, developed and tested at Oakland University. A systems approach was taken in which the designs of the electronic architecture and software were driven by the mechanical requirements and operational needs of the engine, and by the need for dynamometer testing and tuning functions. An ECU, powered by a 68HC12 microcontroller was developed, including a four-layer circuit board designed for EMC. A GUI was written with Visual C++ ® for communication with a personal computer (PC). The ECU was systematically tested with an engine simulator, a 2L Ford engine and a 600cc Honda engine, and finally in Oakland’s 2004 FSAE vehicle.

Transient surface-heat-flux measurements in the exhaust of a SI engine

Surface-heat-flux measurements were performed at two locations in a straight-pipe extension of the exhaust-port of a SI engine. The measured surface-heat-flux history was characterised by a double peak, during the exhaust valve-open period. The largest peak resulted from the action of high-velocity, blowdown gases exiting the combustion chamber at the beginning of the exhaust process. The significantly lower second peak was due to the slower piston-driven gas motion that occurred during the displacement phase. During the closed-valve period, the local surface-heat-flux was found to be relatively low (10-45 kW/m 2 ) in comparison to the peak heat flux (80-288 kW/m 2 ), and to exhibit minimal decay. The predicted heat-flux histories from an engine-simulation analysis, which employed a heat transfer correlation developed by the authors, were in good agreement with the corresponding measured histories during blowdown, however, predictions were relatively poor during the displacement phase, both in magnitude and behaviour.