燃油喷雾的大涡模拟

Large Eddy Simulation of Fuel Sprays

中文关键词: 燃油喷雾  大涡模拟  网格相关性  碰撞模型

英文关键词: fuel spray  large eddy simulation  grid-dependency  collision model

中文摘要:

      采用大涡数值模拟方法对三种不同背压条件下柴油喷雾过程进行了数值模拟，重点研究预测的喷雾贯穿距离以及粒子索特平均半径与计算网格的相关性。计算模型采用单方程亚网格湍流模型、ETAB喷雾粒子破碎模型和基于粒子云的碰撞模型。贯穿距离和索特平均半径的预测值与实验值吻合较好，并实现了预测值与计算网格无关性。通过计算结果对湍流模型和碰撞模型敏感性分析，计算结果表明，采用亚网格湍流模型可以降低计算结果对计算网格分辨率的敏感性，引起网格相关性的主要原因在于碰撞模型的网格相关性。

英文摘要:

      Large eddy simulation approach was employed to simulate diesel fuel spray under three different back pressures, and emphasis was placed on the grid dependency of predicted spray penetration and Sauter mean radius. The numerical formulation adopts one equation subgrid turbulence model, ETAB breakup model and a collision model based on “particle cloud”. The predicted spray penetration and Sauter mean radius are in good agreement with experimental data, and grid-independent results are achieved. Sensitivity study of turbulence model and collision model were also conducted and the results reveal that although the subgrid turbulence model can reduce the sensitivity of the computed results to the mesh resolutions, the grid-dependent collision model is the main affecting factor of the grid-dependency of the predicted results.