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This paper investigates the performance of a double actuator electronic fuel control unit, when installed on a gas turbine engine. The validated mathematical model of the unit is linked to a quasi-linear engine mathematical model. A combination of two operating modes of the unit is used to improve the fuel delivery characteristics. Acceleration and maximum speed governing of the engine are simulated. Two control strategies are investigated. In the first, the fuel flow rate and the engine speed are used as feedback signals. In the second, the N-Dot control, which eliminates the need for fuel flow feedback during engine acceleration, is studied.

To increase the operational range of the vehicle equipped with direct injection gas supply and to eliminate the problems associated with the cryogenic pumps, a composite high pressure vessel is proposed for use as a thermocontrolled tank in vehicles. The test results showed that the liquefied natural gas can be brought from atmospheric pressure to the high pressure required for direct injection in a reasonable time period. Based on these results a mathematical model for the heat transfer to the natural gas was developed and simulated. Three different aspects of gas storage, namely, the initial operational temperature, the gas to vessel mass ratio and the gas weight to vessel volume ratio have been investigated and formulated as objectives for optimization. Due to the presence of different conflicting objectives, the problem was formulated as a nonlinear multi objective optimization problem and then solved.

An attempt is made to develop solenoid operated injectors for diesel engines, to inject natural gas directly into the combustion chamber at high pressure. These new injectors have the size of conventional diesel injectors with small but powerful solenoids located in the former spring chamber, and the spring is moved to a location closer to the nozzle. To provide fast opening and closing of the nozzle, a multiobjective optimization method is used to select the design variables of the injector. The mathematical model used for optimization is developed with the help of experimental results obtained from the solenoid force measurements at transient conditions. The optimization results did show good dynamic performance of the injector, despite the use of a small size solenoid actuator.

In this paper the effects of design parameters on the performance of an electric vehicle are presented. A detailed mathematical model was established using governing vehicle dynamics equations. Ideal energy storage systems were modelled with high order polynomial equations and represented graphically in the form of Ragonne curves. This was followed by the development of a simulation program which was utilized to optimize the design parameters, such as specific energy and mass of the storage system, electric motor operating voltage and electric drive final gear ratio. The effects these parameters had on the objective functions, namely range, acceleration, specific consumption, battery cycle life and cost were investigated. The outlined optimization process is presented in a manner which enables the designer to optimize electric or hybrid electric vehicles.