摘要
为了揭示凹坑冷却结构的强化传热机理,基于第三类边界条件下的一维半无限大瞬态导热模型,用红外热成像仪的瞬态测温技术和金属网快速加热技术,对矩形通道内壁面进行了瞬态传热测量,获得了光滑壁面和带有单个球面凹坑壁面的局部对流换热系数分布,并用油-粉末法对凹坑壁面进行了壁面流场显示,实验雷诺数范围1.58×104~6.36×104。实验发现凹坑强化换热与其诱导形成的涡流结构密切相关,单个球面凹坑引起的涡流可以使凹坑下游边缘附近的局部换热最大增强80%左右,凹坑下游尾迹区域的平均换热增强20%~30%。
To reveal the mechanism of heat transfer enhancement with dimpled wall,local heat transfer coefficient distributions on a wall with a single spheric dimple were experimentally investigated in a rectangular channel.The heat transfer rate on a smooth wall was also measured for comparison.A transient heat transfer method was used by assuming a one-dimensional semi-infinite conduction model during the experiment.Step rising of the mainstream temperature was accomplished by using a fast-response metallic-net hea...
出处
《推进技术》
EI
CAS
CSCD
北大核心
2009年第1期41-45,共5页
Journal of Propulsion Technology
基金
航空科学基金资助项目(05C53014)
关键词
凹坑
涡流
换热系数
红外热像仪
瞬态测量
Dimple
Vortex
Heat transfer coefficient
Infrared thermography
Transient measurement
