Abstract Computational fluid dynamics (CFD) and exergy analysis are conducted to investigate the impact of secondary flow produced by V-ribs on the overall performance of a triangular solar air heater (SAH) duct. For a fixed relative rib pitch (Rp = 10) and relative rib height (Rh = 0.05), the effect of rib inclination (α) is studied using CFD technique for varying Reynolds number (5000 ≤ Re ≤ 20000). Based on the CFD simulation results, empirical correlations capable of predicting Nu and f with an absolute variance of 8.7%, and 4.7%, respectively, are developed. Employing these correlations, exergetic performance analysis is carried out. Maximum effectiveness parameter (e) of 2.01 is obtained for α = 45° at Re = 7500. The exergy analysis reveals that the entropy generated is lower for the ribbed triangular duct compared to the smooth duct with maximum enhancement in exergetic efficiency (ηex) as 23% for α = 45°. The study is extended for the rectangular duct to compare the performance with the ribbed triangular duct SAH (α = 45°). Results show that ribbed triangular duct SAH (α = 45°) is superior over various configurations of the ribbed rectangular duct SAH at higher mass flow rates.

中文翻译：

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增强 V 型肋三角风道太阳能空气加热器的热工水力性能：CFD 和火用分析

摘要 通过计算流体动力学 (CFD) 和火用分析，研究了 V 形肋产生的二次流对三角形太阳能空气加热器 (SAH) 管道整体性能的影响。对于固定的相对肋节距 (Rp = 10) 和相对肋骨高度 (Rh = 0.05)，使用 CFD 技术研究不同雷诺数 (5000 ≤ Re ≤ 20000) 的肋骨倾斜度 (α) 的影响。基于 CFD 模拟结果，开发了能够分别以 8.7% 和 4.7% 的绝对方差预测 Nu 和 f 的经验相关性。使用这些相关性，执行有效性能分析。在 Re = 7500 时，α = 45° 时获得的最大有效性参数 (e) 为 2.01。火用分析表明，与平滑风道相比，肋状三角风道产生的熵较低，α = 45°时火用效率 (ηex) 的最大增强为 23%。该研究扩展到矩形风管，以比较其与带肋三角形风管 SAH (α = 45°) 的性能。结果表明，在更高的质量流量下，带肋的三角形管道 SAH (α = 45°) 优于各种配置的带肋矩形管道 SAH。