| This dissertation investigates by means of computer simulation the potential of a Band Variable-Inertia Flywheel (BVIF) to store energy for an urban transit bus. Replacing both a fixed-inertia flywheel (FIF) and a continuously variable transmission (CVT), the Band Variable-Inertia Flywheel is capable of accelerating a vehicle from rest to a nearly-constant speed, while recovering part of the kinetic energy normally dissipated through braking during the deceleration of the vehicle. After each stop, the stored energy is released to accelerate the vehicle during its next cycle of motion. This type of hybrid propulsion is regarded as particularly suitable for large buses with regular stop-start operation in city traffic.; The performance of the BVIF-integrated bus is evaluated with respect to a comparable conventionally-powered bus. Three alternative designs for a BVIF-integrated bus are proposed and discussed with regard to potential and limitations; the most feasible and efficient design is subjected to computer performance evaluation.; The results of this computer simulation show a fuel saving of up to 30 percent with the BVIF-integrated system. The regenerative braking system is shown to reduce brake wear by a factor of five in comparison with the conventional vehicle, and brake maintenance costs were also projected to decrease significantly. The use of stored energy from the BVIF rather than direct energy from the engine to accelerate the bus decreases the likelihood of environmental air pollution from the vehicle's engine. Finally, the use of the flywheel as the prime source of acceleration would permit the substitution of a smaller engine size, because the highest power demand of the vehicle is during the course of acceleration, thereby reducing the cost and weight of the overall vehicle. |
