Effects of buoyancy and of acceleration owing to thermal expansion on forced turbulent convection in vertical circular tubes—criteria of the effects, velocity and temperature profiles, and reverse transition from turbulent to laminar flow
Effects of buoyancy and of acceleration owing to thermal expansion on forced turbulent convection in vertical circular tubes—criteria of the effects, velocity and temperature profiles, and reverse transition from turbulent to laminar flow
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DOI：
10.1016/0017-9310(73)90135-x
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发表时间：
1973-06
影响因子：
5.2
通讯作者：
Tanaka Hiroaki;Tsuge Ayao;Hirata Masaru;Nishiwaki Nuchi
中科院分区：
文献类型：
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作者：
Tanaka Hiroaki;Tsuge Ayao;Hirata Masaru;Nishiwaki Nuchi
本文研究了流体在竖直管内的湍流传热和动量传递问题。首先，通过考虑浮力和加速度引起的惯性力，研究了圆管内的剪应力分布。结果表明，这两种力的作用方式非常相似，并使壁面附近的剪应力迅速减小。通过考虑速度分布与壁面剪应力梯度的关系，导出了浮力和加速度显著影响的判据。其次，通过假定湍流边界层是由局部发展层叠加而成，提出了浮力和加速度作用下的速度和温度分布的近似计算理论。第三，在上述理论的基础上，提出了湍流向层流反向转变的判据。
In this paper, turbulent heat and momentum transfer for a fluid forced through a vertical tube is considered. First, the authors study a shearing-stress distribution in a tube, by taking the buoyancy force and also the inertia force due to acceleration into consideration. It is proved that the effects of both forces operate quite similarly and result in a very rapid decrease of the shearing stress near the wall. By considering how the velocity profile depends upon the shearing-stress gradient at the wall, the authors deduce the criteria for the prominent effects of buoyancy and acceleration. Second, by assuming that the turbulent boundary layer is constructed by the superposition of the locally developed layers, the authors propose an approximate theory to calculate velocity and temperature profiles under the large effects of buoyancy and acceleration. Thirdly, based on the above theory, a criterion of the reverse transition from turbulent to laminar flow is proposed.