Local distribution of wall static pressure and heat transfer on a rough flat plate impinged by a slot air jet
Local distribution of wall static pressure and heat transfer on a rough flat plate impinged by a slot air jet
复制标题
DOI：
10.1007/s00231-017-1999-2
复制
发表时间：
2017
影响因子：
2.2
通讯作者：
Adimurthy Meda;V. Katti
中科院分区：
文献类型：
--
作者：
Adimurthy Meda;V. Katti
实验研究了狭缝气流冲击粗糙平板壁面静压和传热系数的局部分布。实验参数包括：喷嘴-板间距（Z/Dh= 0.5-10.0）、距驻点轴向距离（x/Dh）、分离肋尺寸（b= 4-12 mm）、雷诺数（Re= 2500 - 20000）。用皮托管和差压变送器记录表面上的壁面静压。采用红外热成像技术捕获目标表面的温度分布。结果表明，在所有喷嘴-板间距（Z/Dh）和肋板尺寸下，壁面静压最大值均出现在驻点（x/Dh= 0）处。壁面静压系数Cp随x/Dh单调减小。在分离肋结构中，亚大气压力很明显，所有肋的射流与板间距达到6.0。在z /Dh= 0.5时，由于肋下的流体加速，亚大气区域更强。随着喷嘴与板间距（Z/Dh）的增大，亚大气区变弱并逐渐消失。在分离的肋骨结构中，观察到两个cpas和nuis的合理增强。增强效果随着肋宽的增加而减小。研究结果可用于优化冷却系统的设计。
The present work experimentally investigates the local distribution of wall static pressure and the heat transfer coefficient on a rough flat plate impinged by a slot air jet. The experimental parameters include, nozzle-to-plate spacing (Z/Dh= 0.5–10.0), axial distance from stagnation point (x/Dh), size of detached rib (b= 4–12 mm) and Reynolds number (Re= 2500–20,000). The wall static pressure on the surface is recorded using a Pitot tube and a differential pressure transmitter. Infrared thermal imaging technique is used to capture the temperature distribution on the target surface. It is observed that, the maximum wall static pressure occurs at the stagnation point (x/Dh= 0) for all nozzle-to-plate spacing (Z/Dh) and rib dimensions studied. Coefficient of wall static pressure (Cp) decreases monotonically withx/Dh. Sub atmospheric pressure is evident in the detached rib configurations for jet to plate spacing up to 6.0 for all ribs studied. Sub atmospheric region is stronger atZ/Dh= 0.5 due to the fluid accelerating under the rib. As nozzle to plate spacing (Z/Dh) increases, the sub-atmospheric region becomes weak and vanishes gradually. Reasonable enhancement in bothCpas well asNuis observed for the detached rib configuration. Enhancement is found to decrease with the increase in the rib width. The results of the study can be used in optimizing the cooling system design.