Coordination Funds

协调基金

• 批准号: 423033110
• 负责人: Professor Dr.-Ing. Heinz Pitsch
• 金额: --
• 依托单位: Institut für Technische Verbrennung (ITV)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/423033110?language=en
• 关键词: Coordination; Funds

The significant improvement of present-day combustion systems used for mobility is an important aspect for the reduction of greenhouse gas emissions. The overarching goal of the Research Unit is to provide, based on systematic analysis of cyclic variations, the foundations for a further optimization of modern spark-ignition (SI) combustion concepts, which lead to considerable improvements of efficiency and the reduction of pollutant emissions. Presently, the operation range of highly optimized SI-engines is limited by the occurrence of unwanted combustion phenomena, such as misfire, incomplete fuel conversion, and engine knock, which are all significantly impacted by cyclic variations. Strategies to minimize the appearance of these phenomena exist, but they typically lead to reduced thermal efficiency and hence increased emissions of carbon dioxide. For a further optimization of SI-engines, it is therefore necessary to extend the operation range either by the reduction of cyclic variations or by their targeted exploitation in a way that ensures stable operation at high efficiency. Accomplishing this goal requires a fundamental understanding of the root causes, the development, and the effects of cyclic variations. However, at present, these are neither completely understood nor can they be predictively described. Using novel experimental techniques combined with innovative modeling and simulation technology, a detailed understanding of these phenomena will be established by performing forward and backward analysis of the multi-scale causal chain, and predictive simulation methods will be developed. For this, data for analysis and validation will be generated from experiments and direct numerical simulations for a hierarchy of different configurations from simple flows all the way to full engine cycles. The experimental data, which will be acquired with highly-accurate laser-based methods, will be unique compared with conventional engine experiments, since special attention will be devoted to initial and boundary conditions, which are of critical importance for numerical simulations. Only this level of detail will enable development and validation of new and highly accurate modeling approaches. On the basis of these data, predictive models for mixing and combustion will be developed and validated. Finally, cause and effect of cyclic variations both for idealized port-fuel-injected and for direct-injected SI-engines will be investigated by a combination of experimental studies and numerical analyses using large-eddy simulations (LES). The goal is the systematic forward and backward analysis of the causal chain to characterize cyclic variations and to identify their various causes in a close interaction of experiment and simulation.

当今用于机动性的燃烧系统的显著改进是减少温室气体排放的一个重要方面。研究单位的首要目标是提供，基于循环变化的系统分析，基础上进一步优化现代火花点火（SI）燃烧概念，从而导致效率的显着提高和污染物排放的减少。目前，高度优化的SI发动机的操作范围受到不期望的燃烧现象的发生的限制，例如失火、不完全的燃料转化和发动机爆震，这些都受到循环变化的显著影响。存在使这些现象的出现最小化的策略，但它们通常导致热效率降低，从而增加二氧化碳的排放。为了进一步优化SI发动机，因此有必要通过减少循环变化或通过以确保以高效率稳定运行的方式对其进行有针对性的开发来扩展运行范围。实现这一目标需要对周期变化的根本原因、发展和影响有基本的了解。然而，目前，这些既不完全理解，也不能预测性地描述。使用新颖的实验技术结合创新的建模和仿真技术，通过对多尺度因果链进行正向和反向分析，将建立对这些现象的详细了解，并开发预测性仿真方法。为此，将从实验和直接数值模拟中生成用于分析和验证的数据，用于从简单流到完整发动机循环的不同配置的层次结构。与传统发动机实验相比，将采用高精度激光方法获得的实验数据将是独特的，因为将特别关注初始和边界条件，这对数值模拟至关重要。只有这样的细节水平才能开发和验证新的高度精确的建模方法。在这些数据的基础上，将开发和验证混合和燃烧的预测模型。最后，循环变化的原因和效果都为理想的端口燃料喷射和直接喷射SI发动机将研究的实验研究和数值分析相结合，使用大涡模拟（LES）。我们的目标是系统的因果链的向前和向后分析，以表征周期性变化，并确定其各种原因在实验和模拟的密切互动。