LARGE EDDY SIMULATION OF FUEL-AIR-MIXING IN A DIRECT INJECTION SI ENGINE
LARGE EDDY SIMULATION OF FUEL-AIR-MIXING IN A DIRECT INJECTION SI ENGINE
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直喷 SI 发动机中燃油空气混合的大涡模拟
DOI：
10.1615/tsfp5.1380
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
J. Janicka
中科院分区：
文献类型：
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作者：
D. Goryntsev;M. Klein;A. Sadiki;J. Janicka
这项工作将Goryntsev等人（2007年）使用大涡模拟（LES）方法对流动和混合场的循环到循环变化的研究扩展到使用CFD KIVA-3V代码（Amsden等人，1989年，他把它扩展到了。特别是循环到循环的变化对接近点火点的燃料-空气混合的影响将被研究。研究的配置代表了“BMBF”通用四冲程直喷式发动机与可变充电运动系统。提供了单相流和喷雾的一些实验数据。它们将用于模型验证。引言对环境兼容和经济型车辆的需求，仍然满足高性能的要求，需要付出巨大的努力来开发创新的发动机概念。然而，这种发动机涉及液体燃料沿着多相流现象，例如液滴蒸发和喷雾燃烧。了解喷雾的演化特性、加热和蒸发以及喷雾与湍流、混合和化学反应等气相现象的相互作用，对于此类工程装置的设计和流动控制具有重要意义。虽然许多实验和基于RANS的数值研究集中在如何深入了解内燃机中的喷雾行为，但LES可能有助于提供更好地理解燃烧室中强烈瞬态现象所需的详细非定常信息。Celik等人（2001年）对内燃机大涡模拟的最新综述主要关注单相流，而Sadiki等人（2006年）则关注湍流两相流。事实证明，汽油直喷（GDI）等现代内燃机概念为满足当前和未来的排放标准提供了很好的机会。特别是用于在部分负荷下实例化分层进气的空气引导直接喷射系统允许优化的燃料消耗和低水平的排放。在这一关键过程中，发动机对流动和混合场的循环变化非常敏感。因此，这项工作将Goryntsev等人（2007年）使用大涡模拟（LES）方法对流动和混合场的循环到循环变化的研究扩展到使用CFD KIVA-3V代码（Amsden等人，1989年）。特别是循环到循环的变化对接近点火点的燃料-空气混合的影响将被研究。本文的主要内容如下。下一节将简要介绍其配置、数值方法和模型。对单相流和两相流的结果作了进一步的介绍和讨论。本文件最后一节概述了主要调查结果。配置和数值模型KIVA-3V代码允许解决三维、非定常、可压缩流体运动方程。守恒方程离散使用有限体积法（FVM）的任意六面体网格应用任意拉格朗日欧拉（ALE）方法。详情参见（Amsden等人，1989，Amsden，1993，Amsden，1997）及其参考文献。KIVA提供了两种不同的RANS模型（ε − k和RNG）来考虑湍流效应，并广泛用于内燃机流体动力学的模拟，特别是缸内流动。当前的研究基于使用经典Smagorinsky模型（Smagorinsky，1963）的LES方法，其已经在代码中实现（Amsden等人，1989年）。在本实施方式中，模型常数取为0.1，遵循典型的文献值。使用方形管道配置来验证新的KIVA-3VLES代码，发现结果与可用的DNS数据非常一致（Goryntsev等人，2005年）。使用标准Smagorinsky SGS模型对KIVA-3V中实现的SGS应力张量进行喷雾模拟。所谓的DDM（Dukowicz的离散液滴模型）（Amsden等人，1989）与拉格朗日，计算粒子，代表包裹的喷雾液滴均匀的属性被应用于喷雾描述。喷雾和流体的相互作用是
This work extends the investigation by Goryntsev et al. (2007) of cycle-to-cycle variations of flow and mixing field using Large Eddy Simulation (LES) method to fuel spray injection driven flows using the CFD KIVA-3V code (Amsden et al., 1989) as extended to LES. Especially the effect of the cycle-to-cycle variations on the fuel-air-mixing close to the ignition point will be investigated. The configuration investigated represents the “BMBF” generic four-stroke direct fuel injection engine with variable charge motion system. Some experimental data for single phase flow and spray are available. They will be used for model validation. INTRODUCTION The call for environmentally compatible and economical vehicles, still satisfying demands for high performance, necessitates immense efforts to develop innovative engine concepts. However, such engines involve liquid fuel along with multiphase flow phenomena such as droplet evaporation and spray combustion. A good knowledge of the spray evolution properties, the heating and evaporation as well as the interaction with the gas-phase phenomena such as turbulence, mixing and chemical reactions is important for the design and flow control of such engineering devices. While numerous experimental and RANS-based numerical investigations concentrated on the way to gain insight into the behavior of the spray in IC-Engines, LES may help in delivering detailed unsteady information needed to better understand the strongly transient phenomena going on the combustion chamber. A recent review of LES in IC-Engines was provided by Celik et al. (2001) focused on single-phase flows while Sadiki et al. (2006) deal with turbulent two-phase flows. It turns out that modern internal combustion engine concepts like the Gasoline Direct Injection (GDI) offer a great chance to meet current and future emission standards. Especially air-guided direct injection systems used to instantiate stratified charge at part load allow for an optimized fuel consumption and a low level of emissions. During this crucial process, the engine is very sensitive to cycle-to-cycle variations of the flow and mixing field. Therefore, this work extends the investigation by Goryntsev et al. (2007) of cycle-to-cycle variations of flow and mixing field using Large Eddy Simulation (LES) method to fuel spray injection driven flows using the CFD KIVA-3V code (Amsden et al., 1989). Especially the effect of the cycle-to-cycle variations on the fuel-air-mixing close to the ignition point will be investigated. The paper proceeds as follows. The configuration, numerical method and models are briefly described in the next section. The presentation and discussion of the results for singleand two-phase flow are given further. The main findings are summarized in the final section of the paper. CONFIGURATION AND NUMERICAL MODELS The KIVA-3V code allows for the solution of the 3dimensional, unsteady, compressible equations of fluid motion. The conservation equations are discretised using the Finite Volume Method (FVM) on an arbitrary hexahedral mesh applying the Arbitrary Langrangian Eulerian (ALE) method. For details see (Amsden et al., 1989, Amsden, 1993, Amsden, 1997) and references therein. KIVA offers two different RANS models ( ε − k and RNG) to account for turbulence effects and is widely used for the simulation of ICE fluid dynamics, especially for in-cylinder flows. The current study is based on a LES approach using the classical Smagorinsky model (Smagorinsky, 1963), which has been implemented in the code (Amsden et al., 1989). In the present implementation, the model constant was taken to be 0.1, following typical literature values. A square duct configuration was used to validate the new KIVA-3VLES code and results were found to be in good agreement with available DNS data (Goryntsev at al., 2005). Simulations of spray were carried out using the standard Smagorinsky SGS model for the SGS stress tensor implemented in KIVA-3V. The so-called DDM (discrete droplet model of Dukowicz) (Amsden et al., 1989) with Lagrangian, computational particles that represent parcels of spray droplets with uniform properties was applied for the spray description. The spray and fluid interactions are