【作者】

Nikola Naranca

【摘要】

该论文已在赫尔辛基举行的第28届CIMAC世界大会上发表，论文的版权归CIMAC所有。 Numerical simulation and virtual design release are key tasks in the large engine development. Due to the large size of the entire product incorporating very high single unit costs leading to a limited number of units, testing possibilities are very limited compared to the automotive or other industries. As design changes are hardly possible after an engine has been built and unexpected maintenance during operation has to be avoided, the design needs to be optimized as much as possible by simulation. The simulation model must cover the real system behavior and results have to be as reliable as possible. In addition, the complexity of installations and the number of variants rises steadily. Engine designers have to consider more complex propulsion lines, enhanced and more flexible operating conditions and various approaches for exhaust gas aftertreatment and compliance with emission regulation standards. This means that the development scope and effort is growing constantly. This stands in contrast to the requirement of reducing development time in order to ensure a shorter time to market. Nevertheless, the simulation infrastructure in most companies is still heavily fragmented and standard workflows are being established only very slowly. Research projects have shown, that approx. 50% of a simulation project is regularly invested in data handling and another 20% in data preparation and modelling. The remaining time for the actual work on results evaluation and interpretation is rather low. These numbers impressively demonstrate the need for standard workflows, for integrated simulation solutions and for a seamless modelling approach with a minimum number of breaks in the toolchain in order to reduce delays due to conversion/migration of models or sub-models. This article describes a highly integrated and consistent simulation workflow for the development of the mechanical drivelines in large engine applications. All simulation tasks are linked to the development process. In order to assure and rate the product quality and maturity only by simulation a virtual design release process is used. The initial crankshaft model is established for the early concept phase including torsional behavior with parameter optimization, baseline bearing and strength analysis. During the engine development process, the model is being enhanced stepwise and technically matured in order to perform 3D multi-body dynamic with multi-axial strength and elastohydrodynamic bearing analysis within the same simulation environment. In a further step, a detailed connecting rod and piston-ring-liner-model is added, enabling piston dynamic and friction simulation and optimization on an overallengine-level. Further on NVH simulation of the combustion engine and finally of the complete application (e.g. genset with driveline, e-machine interaction and skid) is performed. This includes low frequency vibration evaluation due to mass and gas forces as well as high frequent acoustics simulation, considering excitations from valve train, timing drive, piston slap and auxilliaries. The presented workflow and simulation tasks are based on real engine developments and validated by measurement results. As all modeling levels are based on the same data base, integrated in the same simulation environment and in-line with standard development processes, data handling time is reduced and development efficiency is significantly increased. An integrated and seamless simulation approach is therefore an important aspect to manage the complex demands in the development of large engine drivelines.

【会议名称】

第28届CIMAC会议

【会议地点】

芬兰 赫尔辛基

【下载次数】

2

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