Heat Transfer Intensification of a Confined Impinging Air Jet via a Guiding Baffle

IF 2.8 4区工程技术 Q2 ENGINEERING, MECHANICAL

Journal of Heat Transfer-transactions of The Asme Pub Date : 2023-03-08 DOI:10.1115/1.4057051

Hussein M. Maghrabie, M. Attalla, Mustafa Abdelfattah

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引用次数: 0

Abstract

The heat transfer intensification of a confined imping jet was achieved using rough surface, pin fines as well as using modified nozzle such as chamfering, chevron, sweeping, swirling, etc. In the current work, the enhanced cooling process utilizing a single confined air jet impinged on a flat plate using a guiding baffle is implemented. The impacts of Reynolds number (Re) ranged from 500 to 5000, guiding baffle diameter-to-nozzle diameter (D/d) of 2, 4, and 6, and guiding baffle height-to-nozzle to impinging plate distance (h/H) of 1/3, 1/2, and 3/4 on the cooling process are studied. The distributions of surface temperature are acquired experimentally using the thermal infrared camera. As well, the local Nusselt number,(Nu) stagnation Nusselt number (Nu¯st), average Nusselt number,(Nu¯) and average Nusselt number ratio (Nur¯) are evaluated. The results reveal that the enhancement of heat transfer is achieved due to installing a baffle with a D/d of 2 for all values of baffle height and Reynolds number. In addition, the (Nur¯) is increased with increasing the Re in the range from 500 to 2500, then it is decreased by a further increase in in Re. Moreover, based on the experimental results, an empirical correction is proposed to compute (Nu¯) the average Nusselt number depending on Re, D/d, and h/H with a ± 2.65% standard deviation.

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导流挡板密闭碰撞气流的传热强化

采用粗糙表面、钉粒以及倒角、三角、扫角、旋流等改进喷嘴，实现了密闭冲击射流的传热强化。在目前的工作中，利用单个受限空气射流撞击使用导流挡板的平板，实现了强化冷却过程。研究了雷诺数Re为500 ~ 5000，导流板直径与喷嘴直径之比D/ D分别为2、4和6，导流板高度与喷嘴撞击板距离h/ h分别为1/3、1/2和3/4对冷却过程的影响。利用热红外热像仪实验获得了表面温度的分布。同时，对局部努塞尔数(Nu)、停滞努塞尔数(Nu¯st)、平均努塞尔数(Nu¯)和平均努塞尔数比(Nur¯)进行了计算。结果表明，在所有挡板高度和雷诺数值下，安装D/ D均为2的挡板可以实现传热的增强。在500 ~ 2500范围内，(Nu¯)随Re的增大而增大，然后随Re的增大而减小。在此基础上，提出了一种基于Re、D/ D和h/ h的平均努塞尔数(Nu¯)的经验修正方法，标准差为±2.65%。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Heat Transfer-transactions of The Asme 工程技术-工程：机械

自引率

0.00%

发文量

182

审稿时长

4.7 months

期刊介绍： Topical areas including, but not limited to: Biological heat and mass transfer; Combustion and reactive flows; Conduction; Electronic and photonic cooling; Evaporation, boiling, and condensation; Experimental techniques; Forced convection; Heat exchanger fundamentals; Heat transfer enhancement; Combined heat and mass transfer; Heat transfer in manufacturing; Jets, wakes, and impingement cooling; Melting and solidification; Microscale and nanoscale heat and mass transfer; Natural and mixed convection; Porous media; Radiative heat transfer; Thermal systems; Two-phase flow and heat transfer. Such topical areas may be seen in: Aerospace; The environment; Gas turbines; Biotechnology; Electronic and photonic processes and equipment; Energy systems, Fire and combustion, heat pipes, manufacturing and materials processing, low temperature and arctic region heat transfer; Refrigeration and air conditioning; Homeland security systems; Multi-phase processes; Microscale and nanoscale devices and processes.