乙醇-空气液雾两相流动和燃烧的大涡模拟  

Large Eddy Simulation of Ethanol-Air Two-Phase Flows and Combustion

作　　者：李科[1,2] 周力行[1] 

机构地区：[1]清华大学航天航空学院,北京100084 [2]内蒙古科技大学能源与环境学院,内蒙古包头014010

出　　处：《工程热物理学报》2011年第6期965-968,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.50736006);天津大学内燃机燃烧国家重点实验室开放基金资助项目(No.K2010-07)

摘　　要：采用动态Smagorinsky亚网格应力模型,EBU(ED,eddy dissipation)燃烧模型和欧拉拉氏两相流模型,对乙醇-空气湍流两相流动和燃烧进行了大涡模拟(LES)。瞬态模拟结果与实验结果定性一致。在火焰瞬态结构的高温区域,旋涡强度较大,在高温区边缘附近存在的拟序结构有脱落的趋势。乙醇液滴通过喷雾器喷出,液滴粒径在10^(-7)～10^(-5)m范围内。在燃烧装置的燃料进口附近,近喷嘴中心区域,大量液滴聚集在条状湍流拟序结构的周围。LES模拟的统计结果给出的温度分布与实验结果定性一致,但在定量上,模拟值普遍高于实验值。其原因可能是EBU燃烧模型的缺陷,没有考虑亚网格反应率,以及统观一步反应饥理引起的误差。The dynamic Smagorinsky sub-grid scale（SGS）stress model,EBU combustion model and Eulerian-Lagrangian two-phase flow model are used in large-eddy simulation of ethanol-air two-phase flows and combustion.The instantaneous results show that the vorticity is stronger in the high-temperature zone.The droplet sizes are in the range of 10^（-7）to 10^（-5）m.The droplets are concentrated around the strip-shaped coherent structure.The LES statistical results for the temperature give the similar trend as that measured,but quantitatively the simulated temperature is higher than that measured except in the region near the spray atomizer.This discrepancy maybe caused by shortcomings of the EBU combustion model,which ignores the sub-grid scale reaction rate and adopts a one-step global reaction mechanism.The combustion model remains to be improved.

关 键 词：乙醇-空气两相流动 液雾燃烧 大涡模拟 

分 类 号：TK121[动力工程及工程热物理—工程热物理]