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Electric coolant pumps for IC engines are under development by a number of suppliers. They offer packaging and flexibility benefits to vehicle manufacturers. Their full potential will not be realised, however, unless an integrated approach is taken to the entire cooling system. The paper describes such a system comprising an advanced electric pump with the necessary flow controls and a supervisory strategy running on an automotive microprocessor. The hardware and control strategy are described together with the simulation developed to allow its calibration and validation before fitting in a B/C class European passenger car. Simulation results are presented which show the system to be controllable and responsive to deliver optimum fuel consumption, emissions and driver comfort.

The series sequential turbocharging technology is recently gaining attention as the new round of engine downsizing and emission control becomes imperative for the engine manufacturers. The technology is able to provide combined benefits of transient performance, engine downsizing, fuel efficiency and emissions reduction with foreseeable problems of control, packaging and cost. The matching and characterization of the two interactive turbochargers is a challenging exercise. Two important questions are, how should the two machines be sized and what is the best strategy for the turbochargers across the speed range of the engine at full load. This paper addresses these two questions by comparing a variety of matching sizes and presenting an attempt to identify an optimal valve operating schedule in order to achieve the target limiting torque curve.