Simultaneous measurements of velocity and temperature fluctuations in thermal boundary layer in a drag-reducing surfactant solution flow
Simultaneous measurements of velocity and temperature fluctuations in thermal boundary layer in a drag-reducing surfactant solution flow
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DOI：
10.1007/s00348-003-0687-9
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发表时间：
2004
影响因子：
2.4
通讯作者：
Feng-chen Li;Dezhong Wang;Y. Kawaguchi;K. Hishida
中科院分区：
文献类型：
--
作者：
Feng-chen Li;Dezhong Wang;Y. Kawaguchi;K. Hishida
对表面活性剂减阻溶液槽道流动中热边界层的湍流传热机理进行了实验研究。采用双分量激光多普勒测速仪和细丝热电偶探头同时测量了流场的速度和温度脉动。发现了两层热场：具有高温度梯度的高耐热层和具有小温度梯度甚至零温度梯度的层。添加减阻剂的流动的峰值比牛顿流动的峰值大，且峰值位置远离壁面。的分布以与表面活性剂溶液流动中的分布的降低类似的方式被降低，即，与uandv之间的去相关相比，雷诺切应力的抑郁症导致阻力减少;同样，它是由于减少的传热减少的湍流热通量在壁法线方向的流动与减阻表面活性剂添加剂的减少。
The mechanism of turbulent heat transfer in the thermal boundary layer developing in the channel flow of a drag-reducing surfactant solution was studied experimentally. A two-component laser Doppler velocimetry and a fine-wire thermocouple probe were used to measure the velocity and temperature fluctuations simultaneously. Two layers of thermal field were found: a high heat resistance layer with a high temperature gradient, and a layer with a small or even zero temperature gradient. The peak value ofwas larger for the flow with the drag-reducing additives than for the Newtonian flow, and the peak location was away from the wall. The profile ofwas depressed in a similar manner to the depression of the profile ofin the flow of the surfactant solution, i.e., decorrelation betweenvandθcompared with decorrelation betweenuandv. The depression of the Reynolds shear stress resulted in drag reduction; similarly, it was conjectured that the heat transfer reduction is due to the decrease in the turbulent heat flux in the wall-normal direction for a flow with drag-reducing surfactant additives.