甲烷/空气中对撞射流火焰的实验和数值研究

Experiment and numerical research of impinging jet flames of methane/air

关键词:  对撞射流火焰  阴影照片  数值仿真

Key words:  Impinging jet flame  Shadowgraph  Numerical simulation

摘要:

以甲烷/空气为研究对象,利用YA-16多闪光高速照相机对碰撞射流火焰进行了实验研究。基于带化学反应的二维轴对称Navier-Stokes方程,采用带有Superbee限制函数的波传播算法,对该现象进行了数值模拟。结果表明,对撞前,由于Helmhotz不稳定的作用,射流火焰演变成带有涡环的蘑菇云。碰撞后,在其诱导的流场和涡的作用下,形成的火焰杆的直径基本没有变化,火焰盘则沿着碰撞平面往四周发展,而其厚度逐渐变薄。计算结果和实验照片进行了比较,两者符合得较好。

Abstract:

Using YA-16 high-speed photograph technique,a series of experimental shadowgraph images of impinging jet flame for methane/air were recorded.Based on the two-dimensional axisymmetric Navier-Stokes equations coupling with chemical reactions,this phenomena was numerically studied by using wave propagation algorithm with Superbee limiter.The results show that before impinging,jet flames become mushroom cloud with vortex because of Helmhotz instability.After impinging,with influence of the flow and vortex induced the flame,the diameter of flame pole remains,and flame disc expands around impinging plane and its thickness becomes thin.The calculated results are compared with the experiments,and good agreements have be obtained.