旋转U型通道内换热的数值计算

在转速为550 r/min,旋转数为0.0~0.3的范围内,对旋转光滑U通道(AR=1∶4)内换热进行了数值模拟,与文献中换热实验结果的对比表明,数值预测结果从定性趋势上很好地吻合了实验数据。重点研究了进口雷诺数为10 000时通道内速度,温度和努塞尔数的分布规律。结果表明,转弯和旋转会在通道内产生截面二次流,从而造成通道各壁面的换热存在差异;旋转数和浮力参数的变化对通道各部分换热的影响也是不同的。

NUMERICAL SIMULATION OF HEAT TRANSFER IN A ROTATING TWO-PASS RECTANGULAR COOLING CHANNEL (AR=1:4)WITH SMOOTH WALL

Numerical simulations of the heat transfer are presented for a rotating two-pass smooth channel with the aspect ratio AR=1:4. Under the fixed rotation speed (550 rpm), the rotation number is varied from 0.0 to 0.3.The heat transfer comparison between the prediction and the published experimental data shows that predicted results are qualitative agreement with experimental results. The focus of this study is to investigate distributions of mean velocity, mean temperature and Nusselt number for the Reynolds number Re=10000. The results show that the turn and rotation driven secondary flow will change the heat transfer on the channel surfaces. The effect of the local buoyancy parameter or rotation number on the regional Nusselt number ratio in the smooth channel is also analyzed. The heat transfer on each part of the channel is different with the increasing buoyancy parameter or rotation number.