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本文对单壁面加热水平方管通道内混合对流换热进行了实验研究,其中加热面分别为底面、侧面、顶面,Re=1514～3028,Gr~*=2.06×10~6～8.22×10~6;通过对加热面温度进行曲线拟合减小壁面温度测量误差,得到考虑轴向导热的局部Nusselt数的变化规律。实验结果表明侧面加热和底面加热时,局部Nusselt数要明显高于顶面加热的情况;局部Nusselt数在管道前段受Re的影响较大,在后段受Gr~*的影响较大。
In this paper, the experimental study of mixed convective heat transfer in a square tube tunnel with single wall heating was carried out. The heating surfaces were bottom surface, side surface and top surface, Re = 1514-3028, Gr ~ * = 2.06 × 10-6 ~ 8.22 × 10 ~ 6; through the heating surface temperature curve fitting to reduce the wall temperature measurement error, the local Nusselt number of axial thermal conductivity is considered. The experimental results show that the local Nusselt number is significantly higher than that of the top heated in the side heating and the bottom heating. The local Nusselt number is greatly affected by Re in the front section of the pipeline and is affected by Gr ~ * in the latter section.