等截面柱形直肋一维修正传热(近似解)方程及肋传热量的新的简化计算

Modified Heat Transfer Improved Solution and New Simplified Calculation of One-Dimension Cylindrical Pin Fin

针对一维经典肋传热方程及近似解的局限性 ,推出了等截面柱形直肋的一维修正肋传热方程及修正近似解。进一步针对工程中肋端传热时传热量的简化计算法提出了一种新的更为精确的修正简化计算公式。数值比较结果表明 :提出的公式不仅具有原经典公式相同形式及简洁性 ,而且使得肋根部热流率及各截面平均温度的计算精度有了显著的提高 ,并将公式的应用范围扩大至较大 Bi数 ,这为肋片的工程设计优化和应用提供了更为准确而直观的求解方法。图 2表 2参

An improved one dimensional formulation of the pin fin heat transfer equation is proposed, which takes approximation into accounting the nonuniformity of temperature distributions across the cylindrical pin fin, as opposed to the classical approach which neglects transversal temperature gradients. Then an new and more accurate simplified formulation of heat transfer rate at the fin base, while the top of pin fin exist heat transfer, is presented. The numerical results shows that the modified expression and simplified formulation are as simple as that obtained from the classical solution, but accuracy on heat transfer rate at the base and average temperature profiles along the fin is significantly improved. The present analysis extends the applicability range of the very simple one dimensional formulation to considerably larger values of Biot number at the pin fin's later surface. Figs 2 and tables 2.