H_2/N_2/O_2射流扩散火焰的直接数值模拟

DIRECT NUMERICAL SIMULATION OF H_2/N_2/O_2 JET DIFFUSION FLAME

直接数值模拟(DNS),大涡模拟(LES)与雷诺时均模拟(RANS)是数值模拟燃烧流动的三大主要方法,而射流扩散火焰在燃烧理论,实验研究与数值模拟中都扮演着十分重要的角色,本文采用完全可压缩的Naive-Stokes方程,对喷口直径为D=1 mm,Re=2000的射流扩散火焰进行了直接数值模拟.本文首先分析了冷态时H_2,O_2的混合,发现燃料与氧气在流向长度大于6D后的区域混合得十分充分.随后本文分析了燃烧后的统计特性,主要包括速度场,密度,温度以及主要组分与混合分数的分布,并将DNS结果与实验结果进行对比分析.

Direct Numerical Simulation（DNS）,Large Eddy Simulation（LES） and Reynolds Average Numerical Simulation（RANS） are three main approaches to simulate combustion and flow,and jet diffusion flame plays an important role in combustion theory,combustion experiment,and combustion model.This article which adopts compressible Naive-Stokes equations simulates a jet diffusion flame using Direct Numerical Simulation（DNS）.The jet nozzle is D=1 mm and the Reynolds Number is Re=2000.This article first analyzes the mixture of H2 and O2 at cold state and discovers that after downstream equals 6D,the fuel and oxidizer mix very well.After that,the article analyzes the statistics data after ignition,mainly concludes velocity field,density,temperature,main species,and mixture fraction,and the comparison between DNS and experiment also carries out.