Analysis of the opportunities and trade-offs for an 48V electrified air path

Yang Liu, Ramkumar Vijayakumar, Richard Burke

Research output: Chapter or section in a book/report/conference proceedingChapter in a published conference proceeding

2 Citations (SciVal)
70 Downloads (Pure)


The electrification of powertrains is now the accepted roadmap for automotive vehicles. The next big step in this area will be the adoption of 48V systems, which will facilitate the use of technologies such as electric boosting and integrated starter-generators. The introduction of these technologies gives new opportunities for engine airpath design as an electrical energy source may now be used in addition to the conventional mechanical and exhaust thermal power used in super- and turbochargers. This work was conducted as part of the EU funded project “THOMSON” which aims to create a cost effective 48V system enabling engine downsizing, kinetic energy recovery, and emissions management to reduce the environmental impact of transportation. The paper presents a study on an electrified airpath for a 1.6L diesel engine. The aim of this study is to understand the design and control trade-offs which must be managed in such an electrified boosting system. A two-stage boosting system including an electric driven compressor (EDC) and a variable geometry turbocharger (VGT) is used. The air path also include low and high pressure EGR loops. The work was performed using a combination of 1D modelling and experiments conducted on a novel transient air path test facility. The simulation results illustrate the trade-off between using electrical energy from in the EDC or thermal energy in the turbocharger to deliver the engine boost pressure. For a same engine boost target, the use of the EDC allows wider VGT opening which leads to lower engine backpressure (at most 0.4bar reduction in full load situation) and reduced pumping losses. However, electricity consumed in EDC either needs to be provided from the alternator (which increases the load on the engine) or by depleting the state of charge of the battery. The location of charge air coolers (pre- or post- EDC) is also investigated. This changes the EDC intake temperature by 100K and the intake manifold by 5K which subsequently impacts on engine breathing. An experimentally validated model of a water charge air cooler model has been developed for predicting flow temperature.

Original languageEnglish
Title of host publicationEmissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development, Volume 2
PublisherAmerican Society of Mechanical Engineers (ASME)
Number of pages12
ISBN (Electronic)9780791851999
Publication statusE-pub ahead of print - 3 Jan 2019
EventASME 2018 Internal Combustion Engine Division Fall Technical Conference, ICEF 2018 - San Diego, USA United States
Duration: 4 Nov 20187 Nov 2018


ConferenceASME 2018 Internal Combustion Engine Division Fall Technical Conference, ICEF 2018
Country/TerritoryUSA United States
CitySan Diego

ASJC Scopus subject areas

  • Automotive Engineering
  • Mechanical Engineering
  • Fuel Technology


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