中文摘要：

采用了剪切应力输运（SST）k-w两方程湍流模型并考虑近壁低雷诺数的修正对矩形横截面螺旋管内冷却水流动和传热特性进行了数值研究。数值分析了在不同入口雷诺数、曲率半径以及扭距条件下，螺旋管内的温度、速度场以及流线的变化，讨论了螺旋管内、外壁面对流传热系数的差异及产生机理，同时与直通管道传热性能进行了比较。研究发现由于离心力的作用，螺旋管内存在显著的二次流动，管内、外侧壁面对流传热存在差异。旋转一周后，螺旋管即进入了流动稳定状态，入口雷诺数可以显著提升螺旋管整体的对流换热效率，扭矩和曲率对内外壁面传热效果的影响不大，而窄高型的横截面构型可以显著改善螺旋管的传热效果。研究结果对应用矩形横截面螺旋管的冷却设计提供参考。

英文摘要：

A Three-dimensional turbulent forced convective heat transfer and its flow characteristics in a helical rectangular duct are simulated using a shear stress transport （SST） k-co turbulence model and taking into consideration the modified low Reynolds number near the wall. The temperature, flow field and the streamline at different axial locations along the stream are analyzed for different Reynolds numbers, different curvatures and different torsions. The causes of the differences be- tween the inner and outer walls of the helical rectangular ducts are discussed and the differences between the helical duct and straight channel are compared. A second flow in the helical duct caused by the centrifugal effect results in the differences be- tween the inner and outer walls. For the present study, the flow is steady after the first roll. The Reynolds number can en- hance the overall heat transfer, and torsion and curvature do not much change the heat transfer effect. But the rectangular configurations can significantly enhance the heat transfer coefficients. The results obtained from the present investigation are meant to serve as basic data for further cooling design using helical rectangular ducts.