【摘要】 为精确描述内燃机进气过程中的缸内流场动态特性,基于非结构化动网格和有限体积法,应用大涡模拟方法对1台模型发动机进气过程进行三维瞬态数值模拟研究。计算采用动态Smagorinsky亚网格尺度模型,得到缸内速度和湍流黏度分布及其随时间的变化。大涡模拟的计算结果与试验值吻合良好,与RNAS模型相比能更精确地揭示流场的瞬变结构和流动的随机特性。更多还原

【Abstract】 In order to accurately characterize the dynamic behavior of intake flow,three-dimensional simulation of transient inlet flow in a model engine was conducted using the large-eddy simulation(LES) method.The in-cylinder flow structure and turbulence viscosity distribution as well as their temporal evolutions were obtained through numerical computations of dynamic Smagorinsky SGS model.Comparisons between experimental data and LES predicted results show a satisfactory agreement.Compared with RNAS model,LES is superior in predicting more accurately the transient structures and random characteristics of complex in-cylinder turbulent flows.更多还原