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Influence of advanced cylinder coatings on vehicular fuel economy and emissions in piston compression ring conjunction

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journal contribution
posted on 14.11.2019, 09:52 by Nader DolatabadiNader Dolatabadi, Michael ForderMichael Forder, Nick MorrisNick Morris, Ramin RahmaniRamin Rahmani, Homer Rahnejat, Sebastian Howell-Smith
IC engines contribute to global warming through extensive use of fossil fuel energy and emission of combustion by‐products. Innovative technologies such as cylinder de‐activation (CDA), after‐exhaust heat treatment, surface texturing and coatings are proposed to improve fuel economy and reduce emissions of the vehicle fleet. Therefore, study of coating technology through a comprehensive multi‐physics analytical model of engine top compression ring is important to ascertain ways of promoting energy savings. This paper presents a multi‐scale, multi‐physics model of the compression ring‐cylinder bore conjunction, using three alternative bore surfaces. The model comprises ring dynamics, contact tribology, heat transfer and gas blow‐by. Tribological and thermal properties of advanced coatings, such as Nickel Nanocomposite (NNC) and diamond‐like carbon (DLC) are compared with an uncoated steel bore surface as the base line configuration. Such a comprehensive analysis has not hitherto been reported in open literature, particularly with original contributions made through inclusion of salient properties of alternative bore materials for high performance race engines. Power loss and FMEP are evaluated in a dynamometric test, representative of the World‐ wide harmonised Light vehicles Test Cycle (WLTC). The NNC coating shows promising tribological improvements. The DLC coating is detrimental in terms of frictional power loss and FMEP, although it can effectively improve sealing of the combustion chamber. The differences in power loss of nominated bore surfaces are represented as fuel mass and CO emissions, using theoretical and empirical relations. For the first time the paper shows that advanced coatings can potentially mitigate the adverse environmental impacts of spark ignition (SI) engines, with significant repercussions when applied to the global gasoline‐powered vehicle fleet.

Funding

Capricorn Automotive Ltd

Engineering and Physical Sciences Research Council (EPSRC)

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

Applied Energy

Volume

259

Publisher

Elsevier

Version

VoR (Version of Record)

Rights holder

© The Authors

Publisher statement

This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).

Acceptance date

11/11/2019

Publication date

2019-11-21

Copyright date

2020

ISSN

0306-2619

Language

en

Depositor

Dr Nader Dolatabadi Deposit date: 14 November 2019

Article number

114129