环形截面螺旋通道内层流换热热力性能数值模拟  

Numerical Simulation of Thermal-Dynamic Characteristics through a Helical Coiled Tube with Annular Cross Section for Laminar Flow

作　　者：吴双应[1] 陈素君[1] 李友荣[1] 李隆键[1] 

机构地区：[1]重庆大学动力工程学院,重庆400044

出　　处：《核动力工程》2009年第4期86-90,共5页Nuclear Power Engineering

基　　金：重庆市自然科学基金项目(CSTC;2006BB6226)

摘　　要：在恒壁温工况下，对旋转7200环形截面螺旋通道内三维层流换热的热力性能进行数值模拟。研究雷诺数为200～1000、无量纲螺距为0．1--0．2、曲率范围为0．1--0．3、在内环加热外环绝热情况下螺旋通道内不同截面上的温度场分布和速度场分布以及雷诺数、曲率和无量纲螺距对轴向不同截面上平均努谢尔特数和平均摩擦系数的影响。研究结果表明：在人口阶段，二次流作用可以忽略，随着转角增大，二次流作用加强，且垂直于轴向截面的最大速度向通道的外侧移动；轴向截面平均努谢尔特数和轴向截面平均摩擦系数随着雷诺数、曲率和螺距的变化呈现不同的规律，并且和曲率相比，螺距对传热和流动性能的影响程度相对较小。A numerical method for simulating three-dimensional laminar forced convective heat transfer in a helical coiled passage with annular cross section under uniform wall temperature condition is presented. The helical coiled passage is fabricated by bending a 0.03m inner diameter and 0.05m outer diameter straight tube into a helical-coil of two turns. The results presented in this paper cover a Reynolds number range of 200-1000, a pitch range of 0.1-0.2 and a curvature ratio range of 0.1-0.3. The numerical computations reveal the development and distribution of heat transfer and flow fields in the helical coiled passage when the inner annular wall is heated and the outer annular wall is insulated. In addition, the effects of Reynolds number, curvature ratio, and coil pitch on the average friction factor, average Nusselt number at different axial cross-section have been discussed. The results show that the secondary flow is weak and can be neglected at the entrance region, but the effect of the secondary flow is enhanced, the maximum velocity perpendicular to axial cross section shifts toward the outer side of helical coiled passage. Furthermore, the average Nusselt number and friction factor at every different axial location present different characteristics when the Reynolds number, curvature ratio and pitch change. Compared with the curvature ratio, the pitch has relatively little influence on the heat transfer and flow performance.

关 键 词：层流换热 环形截面螺旋通道 热力性能 数值模拟 

分 类 号：TL33[核科学技术—核技术及应用]