航天发动机多孔壁面发汗冷却液膜特性研究  

Exploring Characteristics of Transpiration Cooling Liquid Film on Porous Wall of Rocket Engine

作　　者：李佳明[1] 范建 胡颖[1] 胡春波[1] 

机构地区：[1]西北工业大学,陕西西安710072 [2]北京宇航系统工程研究所,北京100076

出　　处：《西北工业大学学报》2012年第5期768-772,共5页Journal of Northwestern Polytechnical University

基　　金：国家自然科学基金(50976095)资助

摘　　要：为了研究多孔壁面发汗液膜冷却的特性,在对剪切气流驱动液滴变形和运动机理研究的基础上,采用步进电机控制液滴的体积,通过加热多孔壁面将液滴输送至连续剪切气流作用的实验风洞中,分析气流流速、壁面孔隙尺寸以及壁面温度对发汗液膜形状的影响。实验结果表明,剪切气流在推动发汗液膜向前伸展的同时也迫使其向两侧扩张,剪切气流速度超过某一临界速度时,液膜不再向两侧扩张;随着多孔壁面孔隙直径的增大,发汗液膜的面积不断增加,其增加程度逐渐降低;壁面温度越高,发汗液膜面积越小,完全蒸发耗时越少。To our knowledge, there is no paper in the open literature exploring the formation and characteristics of liquid film in transpiration cooling. Based on the previous studies of the movement of the shear flow driven droplets on the surface of a solid body, we explore how transpiration cooling liquid film is formed on the surface. We use a stepping motor to control the volume of a liquid droplet and to transport the liquid droplet to a wind tunnel with constant shear flow through heating the porous wall. Then we analyze the effects of flow velocity, the size of pore and the temperature of porous wall on the formation of liquid film and its evaporation by the shear flow at different speeds. The experimental results, given in Figs. 3 through 7, and their analysis show preliminarily that ： （ 1 ） the shear flow not only pushes and extends the transpiration liquid film but also forces it to expand sideways; when the shear flow velocity exceeds a certain critical value, the liquid film stops its expansion ; （2） the area of transpiration cooling liquid film increases with increasing diameter of pore on the porous wall, but after the diameter of the pore increases to a certain degree, the increase in the liquid film area goes small ; （3） the higher the wall temperature, the smaller are the liquid film area and the evaporation time.

关 键 词：冷却 液膜 多孔 火箭发动机 剪切流 

分 类 号：V434.14[航空宇航科学与技术—航空宇航推进理论与工程]