Influence of speed and frequency towards the automotive turbocharger turbine performance under pulsating flow conditions
Influence of speed and frequency towards the automotive turbocharger turbine performance under pulsating flow conditions
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DOI：
10.1016/j.enconman.2014.01.047
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发表时间：
2014-04-01
影响因子：
10.4
通讯作者：
Martinez-Botas, R. F.
中科院分区：
文献类型：
--
作者：
Padzillah, M. H.;Rajoo, S.;Martinez-Botas, R. F.
汽车行业对低碳应用的需求不断增长，这促使了高效发动机和能量回收装置的开发。尽管全电动等替代动力系统有了重大发展，但其全面部署受到高成本和缺乏吸引力的生命周期能源和排放平衡的阻碍。因此，基于高效内燃机的动力系统仍然被认为是未来几年的主流。传统上，涡轮增压器一直是提高发动机功率的重要工具，但近年来，它被视为一种使发动机小型化的技术。众所周知的事实是，内燃机中的涡轮增压器涡轮机在高度脉动的排气流中操作。许多研究都在探讨涡轮增压器涡轮机内脉动排气的复杂相互作用，但这些现象仍未完全纳入设计阶段。工业实践仍然是基于稳定的性能图来设计和匹配涡轮机与发动机。目前的工作是在朝着将脉动流性能完全集成到涡轮增压器涡轮机设计中的方向更进一步。本文介绍了涡轮增压器涡轮机级全三维CFD模型的开发工作和结果。在20 Hz和80 Hz脉动流入口条件下，以30，000 rpm和48，000 rpm（分别为50%和80%设计速度）进行模拟。完整的验证程序使用冷流实验数据也被描述。在转子前缘的入射角的时间和空间分辨率表明，圆周变化是很小的（7%）相比，它的变化在时间上的脉冲进展。本文的主要目的是研究涡轮机的转速，以及脉动流频率对其性能的关系。结果发现，除了考虑一个附加参数，即冲角时，在涡轮机入口处的脉动压力和涡轮机效率之间没有直接的瞬时关系。本文还打算调查的潜在损失的信息，如果性能参数简单地平均，而不考虑瞬时的影响。(C)2014爱思唯尔有限公司版权所有。
The ever-increasing demand for low carbon applications in automotive industry has intensified the development of highly efficient engines and energy recovery devices. Even though there are significant developments in the alternative powertrains such as full electric, their full deployment is hindered by high costing and unattractive life-cycle energy and emission balance. Thus powertrain based on highly efficient internal combustion engines are still considered to be the mainstream for years to come. Traditionally, turbocharger has been an essential tool to boost the engine power, however in recent years it is seen as an enabling technology for engine downsizing. It is a well-known fact that a turbocharger turbine in an internal combustion engine operates in a highly pulsating exhaust flow. There are numerous studies looking into the complex interaction of the pulsating exhaust gas within the turbocharger turbine, however the phenomena is still not fully integrated into the design stage. Industry practice is still to design and match the turbine to an engine based on steady performance maps. The current work is undertaken with the mind to move one step closer towards fully integrating the pulsating flow performance into the turbocharger turbine design. This paper presents the development efforts and results from a full 3-D CFD model of a turbocharger turbine stage. The simulations were conducted at 30,000 rpm and 48,000 rpm (50% and 80% design speed respectively) for both 20 Hz and 80 Hz pulsating flow inlet conditions. Complete validation procedure using cold-flow experimental data is also described. The temporal and spatial resolutions of the incidence angle at the rotor leading edge suggest that the circumference variation is little (7%) as compared to its variation in time as the pulse progresses. The primary aim of this paper is to investigate the relationship of the turbine speed, as well as the pulsating flow frequency to its performance. It was found that there are no direct instantaneous relationship between the pulsating pressure at the turbine inlet and the turbine efficiency, except when one considers an additional parameter, namely the incidence angle. This paper also intends to investigate the potential loss of information if the performance parameters are simply averaged without considering the instantaneous effects. (C) 2014 Elsevier Ltd. All rights reserved.