Abstract The smooth circular tubes are typically used in air-cooled heat exchangers systems. In literature, various research toward improving the hydraulic/thermal performance by changing the tubes' inner surface topology is found. In the current work, fluid friction and heat transfer characteristics of air-cooled tube heat exchangers with installed ribs and grooves have been numerically compared. Initially, the numerically calculated data of the ribbed tubes are validated /compared to the performance results in the literature. Performance evaluation criteria (PEC), entropy and exergy are numerically investigated for a tube with a group of ribs and grooves over the range of Reynolds number Re = 6700–20,000. Rib radius (r), number of ribs in the same group (Ng), the distance between two adjacent ribs (SL), and pitch between two adjacent groups (p) are the ribs parameters selected to study their effects on flow and heat transfer criteria. Also, the same evaluation criteria are performed on grooved tube with optimal parameters to make a comparison between results. Moreover, streamline patterns and temperature/pressure/velocity/turbulence kinetic energy contours are visually introduced to explicate the physics of heat transfer and pressure drop phenomena and to assess the flow structures inside different ribbed/grooved tubes. For the tubes with high-performance evaluation criteria (PEC), lower and higher entropy and exergy efficiency are determined. Recapitulation results from the technical comparison supported the use of grooved-tubes instead of ribbed-tubes. This is mainly due to lower flow irreversibility accompanied by higher PEC and exergy efficiency than those of ribbed tubes at the same flow condition.

中文翻译：

---

肋/槽管的热设计评估：熵和火用方法

摘要 光滑圆管通常用于风冷换热器系统。在文献中，发现了通过改变管的内表面拓扑结构来改善水力/热力性能的各种研究。在目前的工作中，已经对安装有肋和凹槽的风冷管式换热器的流体摩擦和传热特性进行了数值比较。最初，肋管的数值计算数据与文献中的性能结果进行了验证/比较。在雷诺数 Re = 6700–20,000 的范围内，对具有一组肋条和凹槽的管子的性能评估标准 (PEC)、熵和火用进行了数值研究。肋条半径（r），同组肋条数（Ng），相邻两肋条之间的距离（SL），和两个相邻组之间的节距 (p) 是选择的肋参数，以研究它们对流动和传热标准的影响。此外，对具有最佳参数的沟槽管执行相同的评估标准，以对结果进行比较。此外，流线模式和温度/压力/速度/湍流动能等值线被直观地引入，以解释热传递和压降现象的物理原理，并评估不同肋/槽管内的流动结构。对于具有高性能评估标准 (PEC) 的管，确定了越来越低的熵和火用效率。技术比较的概括结果支持使用凹槽管而不是肋管。