ABSTRACTIn the present work, the use of cylindrical turbulators in a double pipe heat exchanger has been investigated. Cylindrical fin type of turbulators has been placed circumferentially separated by 90° on the outer side of an inner pipe at a regular pitch. Experimental studies were undertaken for different air flow rates in a turbulent regime whose Reynolds number range between 2500 and 10000. Heat transfer characteristics like Nu and friction factor have been experimentally determined. Parametric studies were conducted by changing the pitch and also the orientation of the turbulators. Nu and friction factor were found to increase as the pitch is reduced. A model with alternatively changed orientation outperformed others by exhibiting highest Nu and reduced friction factor.

中文翻译：

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湍流条件下双管换热器圆柱湍流器的实验与数值分析

摘要在目前的工作中，已经研究了在双管换热器中使用圆柱形湍流器。圆柱翅片型湍流器已在内管外侧以规则节距沿圆周间隔90°放置。对雷诺数介于 2500 和 10000 之间的湍流状态中的不同空气流速进行了实验研究。已通过实验确定传热特性，如 Nu 和摩擦系数。通过改变节距和湍流器的方向进行参数研究。发现 Nu 和摩擦系数随着螺距的减小而增加。具有交替改变方向的模型表现出最高的 Nu 和降低的摩擦系数，优于其他模型。