加湿湍流燃烧火焰稳定的速度场特性分析

Analysis of velocity fields characterization of flame stabilization in turbulent diffusion humid air combustion

利用PIV技术对丙烷/空气湍流扩散的冷态、热态及其加湿燃烧的二维瞬时速度场进行测量,得到了燃烧室内部的速度场矢量图和轴向速度等值线图。通过对比分析发现加湿燃烧情况下回流区的长度减小:加湿燃烧空气主流区的流动速度比不加湿燃烧的速度低;在燃气和空气的交界面处加湿燃烧的速度等值线稀疏,速度梯度明显减小。实验结果表明,湿度增加对燃烧火焰的稳定特性具有一定的影响。

An experimental research based on 2D PIV system has been performed in this paper to measure instantaneous velocity fields of propane/air turbulent diffusion combustion in the unreactive flows, reactive flows,and humid air reactive flows. The velocity field vector diagrams and axial velocity contour diagrams have been acquired suecessfully in the flame zone.By contrast,we find that the length of recirculation zone is diminished appreciably on the humid air combustion condition. The flow velocities in the air main flows zone in the humid air combustion are lower than that of in no - humid air combustion. The velocity contours are sparse which iUuminates that the gradient of velocities is reduced remarkable in the interfaces of the fuel and air. The results show the stabilization characteristic of the flames is somewhat affected by the humid.