Abstract Due to the merits of higher heat transfer efficiency, spirally corrugated tubes are widely used in a range of applications for heat transfer enhancement, especially in coaxial heat exchangers. This article studied a novel hybrid smooth and six-start spirally corrugated tube and focused on its heat transfer performance as well as its pressure drop. Firstly, we focused on the secondary flow derived from the centrifugal force due to the continuous spiral structure, and discovered the flow patterns of fluids in the hybrid tube. In this part, we applied models with different lengths of the corrugation part. Then, the corrugation parts connected with a smooth part can be arranged in identical rotation or opposite rotation of the corrugations, where the fluid affected by the corrugation part is still whirling. For the above different models, both heat transfer and pressure drop performances of two corrugation arrangements are investigated. This work reveals the enhanced heat transfer mechanism of the hybrid smooth and spirally corrugated tube and should be of interest to researchers in heat transfer issues of corrugated tubes.

中文翻译：

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混合光滑螺旋波纹管的传热研究

摘要 由于具有较高传热效率的优点，螺旋波纹管被广泛应用于一系列增强传热的应用中，特别是在同轴换热器中。本文研究了一种新型混合光滑六头螺旋波纹管，并重点研究了其传热性能和压降。首先，我们关注连续螺旋结构产生的离心力产生的二次流动，并发现了混合管中流体的流动模式。在这部分中，我们应用了具有不同长度的波纹部分的模型。然后，可以将与光滑部连接的波纹部布置成与波纹同向旋转或反向旋转，其中受波纹部影响的流体仍在旋转。对于以上不同型号，研究了两种波纹布置的传热和压降性能。这项工作揭示了混合光滑和螺旋波纹管的增强传热机制，应该引起波纹管传热问题的研究人员的兴趣。