Large Eddy Simulations of Jet / Tumble Interaction in a GDI Model Engine Flow
Large Eddy Simulations of Jet / Tumble Interaction in a GDI Model Engine Flow
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GDI 模型发动机流动中喷射/翻滚相互作用的大涡模拟
DOI：
10.4271/2004-01-1997
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
J. Hélie
中科院分区：
文献类型：
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作者：
A. Devesa;J. Moreau;T. Poinsot;J. Hélie
流体动力学是内燃机性能的基本机制。采用单相大涡模拟方法研究了直喷式汽油机模型缸内直喷射流与周围翻滚运动的相互作用。模拟已经进行了AVBP代码，它具有与两步泰勒Galerkin（TTGC）计划和壁自适应局部涡粘性模型相关联的细胞顶点离散。为了探讨三维大涡模拟对内流场模拟的适用性，对理想的定容滚转流场进行了计算。一个实验装置已被设计和测量用于启动和验证计算。代表真实的多相GDI发动机动量的气体射流直接喷射到方形燃烧室中。使用适当的正交分解（POD）分析的几个初始条件，以估计周期到周期的变化和两个喷射策略进行了讨论：首先，直射流与翻滚竞争;其次，倾斜的射流，增加动量的翻滚运动。数值计算结果与实验结果的比较表明，注入对初始旋转结构有很大的影响。这种初始翻滚流的涡管在喷射方向上变形。LES结果进行了比较PIV测量。这提供了对3D流转变的更深入理解。循环到循环的变化被证明是最重要的。
Fluid dynamics are essential mechanisms in the performance of internal combustion engines. This work proposes a study of the interaction between a direct injection jet and surrounding tumbling motion in a model Gasoline Direct Injection (GDI) engine chamber using single phase Large Eddy Simulation (LES). Simulations have been performed with the AVBP code which has a cell-vertex discretization associated with a Two-step Taylor Galerkin (TTGC) scheme and a Wall Adapting Local Eddy viscosity model. In order to explore the suitability of the 3D LES to simulate the internal flow, the calculation is performed for an idealistic tumbling flow at constant volume. An experimental set up has been designed and measurements are used to initiate and to validate calculations. A gaseous jet representative of the momentum of the real multiphase GDI engine is directly injected in a square chamber. Several initial conditions using Proper Orthogonal Decomposition (POD) analysis are used in order to estimate cycle to cycle variability and two injection strategies are discussed: firstly, a straight jet that competes with tumble; secondly, an inclined jet that adds momentum to the tumbling motion. Satisfactory evolution of the numerical results compared with experiments is found. 3D calculations show that the injection strongly modifies the initial rotating structure. The vorticity tube of this initial tumbling flow is deformed in the injection direction. LES results are compared to PIV measurements. This provides a deeper understanding of the 3D flow transition. Cycle-to-cycle variations are demonstrated to be of primary importance.