Laminar, transition and turbulent natural convection adjacent to inclined and vertical surfaces
Laminar, transition and turbulent natural convection adjacent to inclined and vertical surfaces
复制标题
倾斜和垂直表面附近的层流、过渡和湍流自然对流
DOI：
10.1016/0017-9310(72)90210-4
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发表时间：
1972
影响因子：
5.2
通讯作者：
E. Eckert
中科院分区：
文献类型：
--
作者：
J. Lloyd;E. Sparrow;E. Eckert
采用电化学方法对竖直和朝上斜板附近的自然对流传质进行了实验研究。进行了局部测量，得到了沿流和跨向的传质分布。在过渡区和湍流区测量了与时间相关的传质速率，测量的局部层流传质系数与分析预测非常吻合，无论是在垂直表面还是在倾斜表面。标志着层流-湍流转变开始的瑞利数随倾角的变化而显著变化，随离垂线的增大而减小。在过渡区域，对于与垂直方向成15度角倾斜的表面，瞬时传质速率和时间平均传质速率在跨度方向上都有明显的变化。与垂直板相比，斜面湍流传质速率的时间脉动具有更大的幅度和周期。时间平均的局部湍流传质系数与瑞利数的1/3次方相关，此外，还表现出明显的倾角依赖性。
Experiments on natural convection mass transfer adjacent to vertical and upward-facing inclined plates were performed by employing an electrochemical technique. Local measurements were made, yielding both streamwise and spanwise mass transfer distributions. Time-dependent mass transfer rates were measured in the transition and turbulent regimes.The measured local laminar mass transfer coefficients agreed very well with analytical predictions, both for vertical and inclined surfaces. The Rayleigh number marking the onset of laminar-turbulent transition varied markedly with the angle of inclination, decreasing with increasing departures from the vertical. In the transition regime, for surfaces inclined at angles greater than 15 degrees to the vertical, significant spanwise variations in both the instantaneous and time-averaged mass transfer rates were in evidence. The timewise fluctuations of the turbulent mass transfer rates were of substantially greater amplitude and period for inclined surfaces than for the vertical plate. The time-averaged, local turbulent mass transfer coefficients were correlated with the one-third power of the Rayleigh number and, in addition, exhibited an appreciable dependence on the inclination angle.