支管结构对T型管内流体混合过程热波动影响

Effect of branch structure on thermal fluctuation fluid mixing in T-junction

中文关键词: T型管道  混合  热波动  大涡模拟

英文关键词: T-junction junction  mixing  thermal fluctuation  large-eddy simulation

中文摘要:

      通过CFD计算流体软件FLUENT,分别对支管无附加结构及支管有附加结构直管、渐扩管、减缩管四种结构的T型管内冷热流体混合过程进行了大涡模拟，获得了管道内部的瞬时温度。将各结构温度云图与速度矢量图、无量纲时均温度及无量纲均方根温度进行了对比。数值结果表明，附加结构的添加使管内流体流型由冲击射流变为偏转射流，显著减小了T型管壁上的温度波动；缩管结构的无量纲均方根值比其他附加结构更小，表明缩管结构更适合用以减小管壁的温度波动。

英文摘要:

      Mixing processes of hot and cold fluids in T-junction without and with additional structures (straight tube,divergent tube,tapered tube) were` simulated by FLUENT using large eddy simulation (LES)approach.Comparisons of the predictions of velocity vector and temperature contour , normalized mean and RMS temperature were performed. The results indicate that adding the additional structures changes the flow type of impinging jets into deflecting jrts, significantly reducing the temperature fluctuations on the wall of T-junction. The normalized RMS temperature of the tapered tube structure is the minimum compared to that of others, which indicates that tapered tube is the best stucture to reduce the thermal fluctuation on the tube wall.