论文标题
从等热板上的自然对流传热
Natural Convection Heat Transfer from an Isothermal Plate
论文作者
论文摘要
使用边界层理论，在1970年代和1980年代开发了垂直和向下的板上的自然对流传热配方，这些公式在雷利数字（$ ra $）上是准确的。向上板的综合公式尚未解决，因为它们不形成常规的边界层。 从热引擎效率的热力学约束中，此处介绍的新方法得出了从等温平板的自然对流传热配方。跨越$ 1 <ra <10^{12} $的四个同行评审数据集的联合具有5.4％的根平方相对误差（RMSRE），来自新的向上朝上的热传输公式。 这种新颖的方法应用于向下的板，优于Schulenberg（1985）公式的4.6％RMSRE，在四个同行评审的数据集上，跨越$ 10^6 <ra <10^{12} $，在四个同行评审的数据集上。 引入谐波平均值作为垂直和向下板板的特征长度度量，将这些矩形板式公式扩展到其他凸形形状，在Hassani和Hollands（1987）的垂直磁盘对流方面达到3.8％RMSRE（1987），而Kobus和Wedekind（1995）（1995）获得了3.2％。
Using boundary-layer theory, natural convection heat transfer formulas which are accurate over a wide range of Rayleigh numbers ($Ra$) were developed in the 1970s and 1980s for vertical and downward-facing plates. A comprehensive formula for upward-facing plates remained unsolved because they do not form conventional boundary-layers. From the thermodynamic constraints on heat-engine efficiency, the novel approach presented here derives formulas for natural convection heat transfer from isothermal plates. The union of four peer-reviewed data-sets spanning $1<Ra<10^{12}$ has 5.4% root-mean-squared relative error (RMSRE) from the new upward-facing heat transfer formula. Applied to downward-facing plates, this novel approach outperforms the Schulenberg (1985) formula's 4.6% RMSRE with 3.8% on four peer-reviewed data-sets spanning $10^6<Ra<10^{12}$. The introduction of the harmonic mean as the characteristic-length metric for vertical and downward-facing plates extends those rectangular plate formulas to other convex shapes, achieving 3.8% RMSRE on vertical disk convection from Hassani and Hollands (1987) and 3.2% from Kobus and Wedekind (1995).
