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In this study, a model of Active Front wheel Steer (AFS) system are developed and tested. In addition, an Integrated Dynamics Control with Front steer (IDCF) controller is also designed to investigate the performance of AFS system when it is integrated with a brake system. The IDCF system composed of an AFS system and a DYC (Direct Yaw moment Control) system of rear wheels. The AFS controller and IDCF controller are compared under several driving and road conditions with and without braking input and steering input. A 8 degree of freedom vehicle model is also employed to test the controllers. The results show that the model of AFS system shows good kinematic steering assistance function. Steering ratio varies depends on vehicle velocity between 12 and 24. Kinematic stabilization function also shows good performance because yaw rate of AFS vehicle tracks the reference yaw rate.

The effect of ignition energy, ignition system and spark plug electrode on initial flame kernel development in a constant volume combustion chamber has been studied. The experiment was done in a quiescent and lean condition. Two different ignition systems are designed and evaluated, and several kinds of spark plugs are also made. The spark time controller is also developed to regulate dwell time and to synchronize ignition time with data acquisition time. The ignition energy is measured at each experimental condition, and the flame propagation is measured by piezoelectric type pressure sensor. The heat release rate and the mass fraction burnt are derived from the combustion pressure. The results show that as the dwell time or the spark plug gap are increased, the ignition energy is increased, which derives higher heat release rate and faster the mass fraction burnt.

In spark ignition engines, the mechanism of transferring electrical energy from an ignition system into the mixture in the spark gap is controlled by many aspects. The major parameters of these aspects are inputs of electrical energy, combustion energy release, and heat transfers. Heat caused by combustion energy is transferred to the spark plug, cylinder head, unburned mixture, and others. This study presents the development and validation of a flame kernel initiation and propagation model in SI engines, and most of the aspects described above are considered during the course of the model development. Furthermore, the model also takes into account the strain rate of the initial kernel and residual gas fraction. The model is validated by the engine experiments, which are conducted in a constant volume combustion chamber.