Natural convection heat transfer between a uniformly heated cylindrical element and its rectangular enclosure
Natural convection heat transfer between a uniformly heated cylindrical element and its rectangular enclosure
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DOI：
10.1016/0017-9310(92)90075-4
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发表时间：
1992-10
影响因子：
5.2
通讯作者：
N. K. Ghaddar
中科院分区：
文献类型：
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作者：
N. K. Ghaddar
采用谱元法对矩形封闭空间内水平均匀加热圆柱体的自然对流换热进行了数值研究。外壳壁是等温的，并且假定流动是层流和二维的。在不同的热通量施加到气缸的流动和热行为的动力学进行了研究。据发现，平均努塞尔数，Nua，随着瑞利数，Raa，根据形式Nua =C1（Raa）C2，其中C1和C2是经验常数，取决于所选择的尺度λ a的一般相关性。所得的相关常数C2类似于先前公布的相关常数的基础上的实验数据。最高的热传递率发生在顶壁处。对于所有检查的热通量，最大的空气速度是在一个距离约九个圆柱直径沿着垂直中心线以上的加热圆柱。
A numerical study of natural convection heat transfer from a uniformly heated horizontal cylinder placed in a large air-filled rectangular enclosure, is performed using a spectral element method. The enclosure walls are isothermal and the flow is assumed laminar and two-dimensional. Dynamics of the flow and the thermal behavior is studied at various heat fluxes applied to the cylinder. It is found that the mean Nusselt number,Nua, varies with Rayleigh number,Raa, according to a general correlation of the formNua=C1(Raa)C2, whereC1andC2are empirical constants that depend on the chosen scale lengtha. The resulting correlation constantsC2are similar to previously published correlation constants based on experimental data. The highest heat transfer rates out of the enclosure occur at the top wall. For all examined heat fluxes, the maximum air velocity is at a distance of about nine cylinder diameters along the vertical centerline above the heated cylinder.