东北大学学报(自然科学版) ›› 2005, Vol. 26 ›› Issue (5): 484-487.DOI: -

• 论著 • 上一篇    下一篇

竖壁对流换热系数计算模型的探讨

孙志礼;闫明;李国权   

  1. 东北大学机械工程与自动化学院;东北大学机械工程与自动化学院;沈阳发动机设计研究所 辽宁沈阳 110004
  • 收稿日期:2013-06-24 修回日期:2013-06-24 出版日期:2005-05-15 发布日期:2013-06-24
  • 通讯作者: Sun, Z.-L.
  • 作者简介:-
  • 基金资助:
    国防"十五"规划预研基金资助项目(APTD 1002 005)

On the convection coefficient of incompressible fluid flows at varying velocity along vertical plane

Sun, Zhi-Li (1); Yan, Ming (1); Li, Guo-Quan (2)   

  1. (1) School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004, China; (2) Shenyang Aeroengine Research Institute, Shenyang 110015, China
  • Received:2013-06-24 Revised:2013-06-24 Online:2005-05-15 Published:2013-06-24
  • Contact: Sun, Z.-L.
  • About author:-
  • Supported by:
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摘要: 根据流体边界层理论,研究了高普朗特数常物性不可压缩流体在重力作用下,沿竖直壁面无初速度加速流动过程中速度边界层和热边界层的形成规律,给出了速度边界层和热边界层的厚度函数·据此,研究了该模型下对流换热系数的计算方法,推导出计算公式·在短距离流动中,该模型的速度边界层和热边界层较流体外掠水平板模型厚,换热较弱,因此对流系数较小·工程实际中的许多换热问题都可以简化成流体在重力作用下沿竖直平板流动模型·把该模型下得到的对流系数公式应用于飞机附件机匣的传热计算中,得到了比较精确的结果·

关键词: 竖壁, 对流换热系数, 边界层, 重力

Abstract: Based on the boundary layer theory, the rules of the formation of both velocity and thermal boundary layers of an incompressible fluid flowing at zero initial velocity along a vertical plane under the action of gravity are discussed, of which the fluid is featured with a big Prandtl number and constant thermal property. Computing formulas of thickness of both velocity and thermal boundary layers are given. Then, based on these formulas the calculation method on the convective heat coefficient is discussed further with a mathematical expression derived in detail. Compared with the model that the fluid flows along a horizontal plane, both the velocity boundary layer and thermal layer become thicker and the convection heat transfer is less turbulent in short distance flow. Many problems of heat transfer in actual engineering can be simplified as the models that fluid flows along vertical plane under the action of gravity. Applying these formulas in the thermal analysis of the gearbox attached to an aeroengine, an accurate result was obtained.

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