The Ultraboost project outlined in this paper seeks to develop a highly pressure-charged, downsized, spark ignition engine that is capable of a 35% reduction in tailpipe CO2 emissions over a naturally aspirated 5.0L V8 while still maintaining performance, emissions and transient response. This project is especially ambitious since, in order to achieve this level of fuel economy improvement, a 60% reduction in engine displacement is targeted with a BMEP of greater than 30bar. What is more, achieving these targets in a gasoline engine with stoichiometric fuelling requires careful design and component selection in order to address the many challenges surrounding gasoline combustion under such high boost pressures. This paper describes a critical examination of the competing requirements of a heavily downsized, gasoline engine with a specific focus on the role of the boosting system in delivering these requirements. From this analysis, the optimal base boosting system configuration is investigated. In addition, a number of boosting technologies, ranging from the novel to the more traditional, are discussed in view of their ability to fulfil a role on the Ultraboost engine. A set of assessment criteria is presented in order to facilitate the selection process. Finally, a 1-D GT-Power model of the Ultraboost engine equipped with the different boosting systems was used to generate an informed rating of all boosting options and permit a reliable comparison with respect to the targets of the project. © The author(s) and/or their employer(s), 2012.
|Original language||English (US)|
|Title of host publication||Institution of Mechanical Engineers - 10th International Conference on Turbochargers and Turbocharging|
|Publisher||Woodhead Publishing Limited80 High StreetSawston,Cambridge,CB22 3HJ|
|Number of pages||15|
|State||Published - Jan 1 2012|