热绕流流场显示实验研究及数值分析

VISUALIZED EXPERIMENTAL RESEARCH AND NUMERICAL ANALYSIS ON THE THERMOAROUNDFLOW

一、引言 当流体尤其是气体流过局部加热区域时,会发生类似流体绕流物体的现象,这种绕流被称之为热绕流。文献[1]首先提出了热绕流的概念,并指出不均匀加热场是导致热绕流的直接原因。航空发动机燃烧室中不均匀加热场产生的热绕流,将对燃烧室内气流结构产生较大影响。热绕流使雾化油滴偏离冷态轨线,造成壁面过热和积碳;

This paper describes a visualization experiment study. The distinct photographs of the ther-moaroundflow field are got at first by using heating without object. It has demonstrated the correctness of prediction of thermoaroundflow. Some characteristics of this flow are as follows through observating photographs: 1. The contour of thermoaroundflow zone looks like two parallel lines downstream of the heating point. Sometimes two lines are a little diffused. 2. No pressure recovery occurs behind the thermoaroundflow zone. 3. The width between two outlines depends on heating quantity and thermodynamical process in the zone. These results qualitatively consist with the numerical calculation.