管内插入旋流片的流动和传热的数值模拟

Numerical simulation of flow and heat transfer inside tube with regularly spaced twisted-tapes

为了获得较好的传热性能,提出一种在缩放管内间隔插入旋流片的复合强化传热方法。采用水为流动介质,在湍流状态下,通过数值模拟,详细研究了缩放管内插入旋流片的速度场与热流场的分布特性及其相互间的协同。对缩放管插入不同结构旋流片的热阻性能与缩放管和光滑管进行了比较,模拟结果表明,在相同条件下,传热系数和阻力系数最大分别提高25%,120%,120%,370%。缩放管与旋流片的复合使用能有效地改善速度场和温度场的协同程度,是提高换热性能的一个有效手段。

In order to enhance the heat transfer,a method that combines the converging-diverging tube and the spaced twisted tape was presented.The numerical analysis was carried out to study the field coordination between velocity and heat flow fields of water turbulent flow inside a converging-diverging tube with regularly spaced twisted-tapes.The thermal hydraulic characteristics of converging-diverging tube with regularly spaced twisted-tapes,converging-diverging tube and smooth circular tube were compared each other.The results indicate that the heat transfer coefficient and the pressure drop factor are increased by 25%,120%,120% and 370% respectively.The compound heat transfer enhancement of converging-diverging tube and spaced twisted-tapes effectively can improve the coordination between velocity and temperature gradient fields.It is an effective method for improving the heat transfer performance.