纵向内翅片管对流换热特性的实验研究及数值模拟

传热强化技术由于能使换热设备的效率提高，一直受到科技界和工业界的重视．一般认为翅片在强化传热中的作用主要是增加了热阻较大一侧流体的面积，从而减小了以总面积计算的热阻．在管外侧加翅片是强化管外换热的最普遍方式之一．相对而言，利用内翅片管强化换热的研究工作开展得比较少．本文对一种新型内翅片管的传热特性进行了实验研究，并通过数值仿真与实验数据进行了比较和分析．

Experimental study and numerical simulation on convective heat transfer and pressure drop of internally longitudinal finned tube

The fluid flow and heat transfer characteristics of internal longitudinal finned tube were investigated experimentally,and were compared with those of circular annulus tube. It was shown that the internally longitudinal finned tube had better heat transfer performance than the circular annulus tube with increase of pressure drop simultaneously.Numerical results based on the realized k-ε turbulence model agreed well with the experimental results.It was found that there existed a critical Reynolds number, that is, when Reynolds number was less than the critical value, the Nusselt number of internally longitudinal finned tube was smaller than that of circular annulus tube in laminar flow.In addition,the Reynolds number for the transition from laminar to turbulent flow was greatly decreased due to the existence of internal fins.