管内流体的振荡传热分析

流体在管内的轴向振荡运动可以明显地增强热、质的传输能力。有关的传质研究开展较早,传热方面的研究正在日益受到重视,振荡流体的传热实验和理论分析已取得了初步成果。本文采用数值分析方法求解长圆管中振荡流体的速度和温度分布,并在此基础上计算流体的轴向传热热流。计算结果可用有效导温系数a_e表示为: a_e/a=F(W_om,ΔS/R,Pr) 的函数形式。计算与实验数据和理论分析解的比较表明,它们是基本符合的。 

ANALYSIS OF HEAT TRANSFER OF FLUIDS OSCILLATING WITHIN PIPES

Heat transfer can be enhanced when fluid oscillates axially within pipes. A numerical analysis is given using the finite difference method. The relationship derived from differential equations and unambiguous conditions is written in theform ofwhere ae- the effective thermal diffusivity ,a-the thermal diffusivity, AS-the tidal displacement of oscillation ,R-the radius and L-the length of the pipe. The results obtained show that ae/a is independent of L/R as L>>ΔS and proportional to the square of AS/R, and its value increases with an increase in Wom or Pr. The numerical solution is in good agreement with the data of experiments.