The numerical model of the pipes of a flat plate solar collector (FPSC) with several nozzles has been investigated in the present study. Indeed, the effect of the number of nozzles of the swirl generator on the entropic characteristics has been evaluated. The nozzles were applied for improving the performance of FPSC. For evaluating the proposed system based on the entropy concept, the effect of injection angle and mass flow rate has been considered. The selected injection angles were 30°, 45°, 60°, and 90°. Also, the total mass flow rates entered from all of the nozzles were 0.2 kg/s, 1 kg/s, and 2 kg/s. The effect of said variables on frictional and thermal entropy generations was analyzed; then, the overall energetic-entropic performance of the system was predicted using several dimensionless parameters including N_E, N_S, Nu, and heat transfer improvement (HTI). Moreover, Witte-Shamsundar efficiency () was applied to pinpoint the efficiency of the system. The highest value of HTI and was 1.7 and 0.9 that achieved by “single-nozzle; A90-D50-N12.5-M0.2” and “quad-nozzle; A30-D50-N12.5-M2,” respectively.

中文翻译：

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平板太阳能集热器中旋流发生器喷嘴数量的影响：熵分析

在本研究中已经研究了具有多个喷嘴的平板太阳能收集器 (FPSC) 管道的数值模型。实际上，已经评估了涡流发生器的喷嘴数量对熵特性的影响。喷嘴用于提高FPSC的性能。为了评估基于熵概念的建议系统，已经考虑了喷射角和质量流量的影响。选定的注射角度为 30°、45°、60° 和 90°。此外，从所有喷嘴输入的总质量流量为 0.2 kg/s、1 kg/s 和 2 kg/s。分析了所述变量对摩擦和热熵产生的影响；然后，使用包括 N _E在内的几个无量纲参数来预测系统的整体能量熵性能，N_小号中，Nu ，并且热传递改善（HTI）。此外，应用 Witte-Shamsundar 效率 ( )来确定系统的效率。HTI 的最高值是“单喷嘴”达到的 1.7 和 0.9；A90-D50-N12.5-M0.2”和“四喷嘴；A30-D50-N12.5-M2”分别。