Turbulence Dissipation in a Free-Surface Jet of Water and Its Effect on Local Impingement Heat Transfer From a Heated Surface: Part 2—Local Heat Transfer
Turbulence Dissipation in a Free-Surface Jet of Water and Its Effect on Local Impingement Heat Transfer From a Heated Surface: Part 2—Local Heat Transfer
复制标题
自由表面水射流中的湍流耗散及其对受热表面局部冲击传热的影响：第 2 部分 - 局部传热
DOI：
10.1115/1.2822330
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发表时间：
1995
影响因子：
--
通讯作者：
F. Incropera
中科院分区：
文献类型：
--
作者：
D. H. Wolf;R. Viskanta;F. Incropera
本文给出了平面自由表面水射流法向均匀加热表面的局部换热数据。通过采用不同的喷嘴类型(平行板和会聚喷嘴)和流动操纵器(金属丝栅和筛网)来改变射流的水动力条件，以研究射流湍流与局部冲击换热的关系。不同喷嘴条件下的流动结构在一篇配文(Wolf et al.，1995)中得到了报道，本文使用这些结果来解释它们对局部换热的影响。除了定性的解释外，还建立了向湍流转变的开始和停滞点处的无因次对流系数的关联式。结果表明，较高的射流湍流度可以在离驻点较小的流向距离处诱导出向湍流边界层的过渡。湍流强度对对流系数的影响约为1/4次方。
This paper presents local heat transfer data for a planar, free-surface jet of water impinging normal on a uniformly heated surface. The hydrodynamic conditions of the jet were altered through the use of different nozzle types (parallel-plate and converging) and flow manipulators (wire grid and screens) to investigate the relationship between jet turbulence and local impingement heat transfer. The flow structures for each of the various nozzle conditions are reported in a companion paper (Wolf et al., 1995), and results are used in this paper to interpret their effect on local heat transfer. In addition to qualitative interpretations, correlations are developed for both the onset of transition to turbulence and the dimensionless convection coefficient at the stagnation point. Higher levels of jet turbulence are shown to induce transition to a turbulent boundary layer at smaller streamwise distances from the stagnation point. The effect of stream-wise turbulence intensity on the convection coefficient is shown to scale approximately as the one-quarter power.