【作者】

Simon Brewster，Martin Weinrotter,Aitor Larralde

【摘要】

论文已在上海2013年CIMAC大会上发表，论文版权归CIMAC所有。 The increasing global demand for power generation and transportation presents a significant opportunity to the world's large engine producers, but presents a key question regarding the protection of our environment and preservation of our natural resources. To meet this challenge requires the introduction of higher efficiency and cleaner engines to the market that extend the known boundaries of performance whilst ensuring product reliability. The successful delivery of these new engines with competitive time to market demands a leap in development philosophy and method. This paper presents the design approach for a single cylinder engine that in close combination with a powerful analysis process enables the significant reduction of development cost and duration, whilst substantially enhancing the fundamental reliability achieved in new product development. Traditionally single cylinder engines have been applied to the early life evaluation of combustion processes. As such the flexibility in configuration, greater refinement in test control and measurement, reduced costs of prototype parts and operation, and reduced test facility demands have accelerated the development of ever cleaner and more efficient combustion systems. Coupled with assessment of the combustion process there has existed the opportunity for the preliminary durability assessment of certain performance related components. This has offered promise in particular due to the much-reduced overhead in operation. However, there remains a substantial and unrealised opportunity in the application of single cylinder engines to the accelerated validation of multi-cylinder engine function and reliability. In this paper the authors lay out this opportunity and the approach to deliver to market both class leading functionality and reliability. At first the boundary conditions for operation representative of a multi-cylinder engine maybe established through the coupled use of multi-cylinder and single cylinder engine simulations. The gas exchange processes that influence cylinder filling and trapping of residual fractions, charge motion, and transport of emissions maybe determined such that early stage confirmation of the boosting strategy can be given. Simulation of whole engine cooling and lubrication flows coupled with detailed analysis of individual cylinder operation gives confirmation of operating boundary conditions and enables the single cylinder replication of heat exchange processes and component thermal loading, lubrication and friction. Secondly, the architecture of the single cylinder engine is created such that the maximum commonality with engine hardware maybe achieved. Evidently this would include the replication of bore and stroke, but also deck height, connecting rod length and cylinder bore offset. Ensuring the use of common big end bearings and entire valvetrain geometry will then enable not only the use of common cylinder head and piston assemblies, but also connecting rod, liner and all valve gear. The development of rapid prototyping methods which align with production design, materials and manufacturing processes ensures the seamless transfer of designs to the production supply chain. Thirdly, and with the foundation of representative components operating under representative conditions, it becomes possible to significantly extend the validation of both function and reliability. With precise measurement of temperature, pressure and strain the thermal and mechanical performance of components may be confirmed. Further, with representative thermal and mechanical loading, and component deformation and dynamics, the performance of the piston and cylinder liner systems, valvetrain kinetics, and rotating and reciprocating friction may be confirmed.

【会议名称】

第27届CIMAC会议

【会议地点】

上海

【下载次数】

2

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