Influence of advanced cylinder coatings on vehicular fuel economy and emissions in piston compression ring conjunction
Influence of advanced cylinder coatings on vehicular fuel economy and emissions in piston compression ring conjunction
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DOI：
10.1016/j.apenergy.2019.114129
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发表时间：
2020-02-01
期刊：
影响因子：
11.2
通讯作者：
Howell-Smith, S.
中科院分区：
文献类型：
--
作者：
Dolatabadi, N.;Forder, M.;Howell-Smith, S.
内燃机通过大量使用化石燃料能源和排放燃烧副产品，加剧了全球变暖。为了提高燃油经济性和减少车辆排放，提出了诸如气缸钝化（CDA）、排气后热处理、表面纹理和涂层等创新技术。因此，通过发动机顶压环的综合多物理场分析模型研究涂层工艺，对确定促进节能的途径具有重要意义。本文提出了压缩环-缸孔连接的多尺度、多物理场模型，采用三种不同的孔面。该模型包括环动力学、接触摩擦学、传热和吹气。将纳米镍复合材料（NNC）和类金刚石碳（DLC）等先进涂层的摩擦学和热性能与未涂层的钢孔表面进行比较。如此全面的分析迄今尚未在公开文献中报道，特别是通过包括高性能赛车发动机替代孔材料的显着特性而做出的原始贡献。功率损耗和FMEP在动力测试中进行评估，代表全球统一轻型车辆测试周期（WLTC）。NNC涂层具有良好的摩擦学性能。DLC涂层在摩擦功率损失和FMEP方面是不利的，尽管它可以有效地改善燃烧室的密封性。在指定的膛面功率损失的差异表示为燃料质量和CO排放量，使用理论和经验关系。这篇论文首次表明，先进涂层可以潜在地减轻火花点火（SI）发动机对环境的不利影响，当应用于全球汽油动力车辆时，将产生重大影响。
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.