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采用数值模拟方法研究了一个平行圆柱体在层流脉动流中的温度边界层特性。数值模拟结果与实验数据一致。研究发现脉动流中平行圆柱体形成了形状不规则但相对稳定的温度边界层,并在流动方向上周期性脉动。脉动流中平行圆柱体的温度边界层平均厚度小于稳定流动下的温度边界层平均厚度,并以脉动流的频率进行脉动。此外,脉动流中平行圆柱体的壁面温度小于稳定流动下的壁面温度,表明脉动流下圆柱体的对流传热得到了强化。在一个脉动周期内,圆柱体在后半周期的温度边界层厚度和热阻均小于前半周期的温度边界层厚度和热阻。
The temperature boundary layer characteristics of a parallel cylinder in laminar pulsatile flow were studied by numerical simulation. The numerical simulation results are consistent with the experimental data. It is found that the parallel cylinders in the pulsating flow form an irregular but relatively stable temperature boundary layer and periodically pulsate in the flow direction. The average thickness of the temperature boundary layer of the parallel cylinder in the pulsating flow is less than the average thickness of the temperature boundary layer under steady flow and pulsates at the frequency of the pulsating flow. In addition, the wall temperature of the parallel cylinder in the pulsating flow is less than the steady-state wall temperature, indicating that the convective heat transfer of the pulsating flow-down cylinder is enhanced. During one pulsation period, the thickness and thermal resistance of the cylinder at the temperature of the second half of the cycle are both less than those of the first half of the temperature boundary layer.