Abstract In the present work, the thermal performance of impinging jet double pass solar air heater is investigated experimentally. A corrugated wavy plate consists of circular holes, each of 7.66 mm in diameter on the crest region are used to provide the impinging jets of air that provide 1.4%–0.48% plate perforation. While, the double pass is provided by circulating the air first through the channel formed between back and lower corrugated plates and then through another wavy channel formed between two corrugated plates. To provide thermal backup and increase heat transfer to air, two design configurations are investigated i.e. Design-I without porous media (100% porosity) and Design-II with porous media (95%–98% porosity) in the wavy channel. Moreover, the deep insight on physics of fluid using CFD tool is presented in the extent of this work. It is recommended to operate the present solar air heater designs at the mass flow rate of 0.04 kg/s, bed porosity of 98% and impinging plate perforation of 0.48% to have the best thermal performance. Whereas, the maximum thermal efficiency and thermohydraulic efficiency of 94% and 84% is obtained for Design-I, which is about 7.5% and 19%, respectively high compared to Design-II.

中文翻译：

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利用圆形射流冲击提高太阳能空气加热器的热性能

摘要 在目前的工作中，对撞击射流双通道太阳能空气加热器的热性能进行了实验研究。波纹板由圆孔组成，波峰区域的每个圆孔直径为 7.66 毫米，用于提供冲击空气射流，提供 1.4%–0.48% 的板穿孔。同时，通过使空气首先通过形成在后波纹板和下波纹板之间的通道然后通过形成在两个波纹板之间的另一个波浪形通道循环空气来提供双通道。为提供热备份并增加向空气的热传递，研究了两种设计配置，即在波浪形通道中没有多孔介质（100% 孔隙率）的 Design-I 和具有多孔介质（95%–98% 孔隙率）的 Design-II。此外，在这项工作的范围内，还展示了使用 CFD 工具对流体物理的深刻见解。建议在 0.04 kg/s 的质量流量、98% 的床层孔隙率和 0.48% 的冲击板穿孔下运行当前的太阳能空气加热器设计，以获得最佳的热性能。而设计-I 获得的最大热效率和热工水力效率分别为 94% 和 84%，与设计-II 相比分别高约 7.5% 和 19%。