场协同理论对充分发展湍流传热性能的数值分析

在充分发展的湍流流动中，时均温度梯度和时均速度矢量闻的夹角θ是控制其对流换熟强度的重要因素之一．本文通过对两种异型管——横纹管和缩放管的数值模拟，得出：雷诺数Re恒定时，流向方向上↓△T.cosθ的变化规律与局部Ｎu数的分布规律相似．改变几何参数，如肋高或收缩段的长度，可改变θ角的分布．

A Numerical Analysis of Thermal Characteristics of Fully-developed Turbulent Flow with the Field Synergy Theory

The angle θ between dimensionless time-averaged temperature gradient and velocity vector is oneof the main factors to dominate the heat transfer ability of fully-turbulent flow. Numerical investigations arecarried out to examine the angle in a 2-D flow passage of two kinds of tubes, transversely corrugated andconvergent-divergent tube. The calculated results indicate that the variations of T @ cos θ are similar to thelocal Nusselt number along the stream-wise direction while Reynolds number is constant. The geometrical pa-rameters, for example, rib height or converging length can change the angle θ.