Over the last few years there has been increasing level of environmental awareness both publicly and commercially. Depleting oil reserves, high fuel prices, environmental taxes, and challenging emissions targets have resulted in increasing pressure on the automotive industry to produce powertrain solutions which reduce fuel consumption and emissions. As a result of these increasing demands, the automotive industry has been investing and developing new technologies in order to reduce fuel consumption. One of the most notable of these new technologies has been the hybrid powertrain; the first production hybrid vehicle being introduced by Toyota, implementing a powersplitting hybrid system which can make use of series and parallel hybrid power paths. Since the introduction of this vehicle, many more hybrid vehicles have come to the market, where constant development is providing improvements in fuel consumption.This thesis details the work that has been carried out to investigate the performance potential of a series of novel hybrid vehicle powertrains which use of the Milner continuously variable transmission (MCVT). Each hybrid powertrain was selected as a system which has the potential to provide all of the functionality of the current Toyota power-splitting powertrain without suffering from its limitations, and providing additional system flexibility. The aim of the project was to assess the fuel economy and emissions characteristics of each of the proposed hybrid powertrains.The work undertaken throughout this study includes the development of full system models for each of the proposed hybrid vehicle configurations, alongside a full system model of an equivalent conventional manual vehicle powertrain. Experimental testing was also carried out on the internal combustion engine from which the simulation work was based, where exhaust emissions data were obtained.This thesis investigates the capability of each hybrid system to provide the required functionality, and the fuel economy performance of each of the powertrain configurations. A sensitivity analysis is made into the impact of each of the vehicle components on the overall vehicle fuel economy. An emissions analysis is made, comparing the total exhaust emissions from that of the hybrid vehicle powertrains with that of the conventional manual system. Recommendations are made for the selection and development of the hybrid vehicle system and components in order to maximise fuel economy and minimise total exhaust emissions.
|Date of Award||30 Apr 2012|
|Supervisor||Sam Akehurst (Supervisor)|