同一水平面上に等間隔配置された水平加熱円柱列まわりの自然対流の伝熱特性

抄録

Natural convective heat transfer from a horizontal array of heated circular cylinders to air has been investigated experimentally. The average heat transfer coefficients from the cylinders have been measured by varying the diameter d=8.4-20.4mm, the numbers of the cylinder N=1-14, and the horizontal spacing G=3.6-50.6mm between cylinders. The coefficients for fixed spacing G increase first with the number of cylinders from N=1 to 7, while they remained unchanged with further increase in N. Besides, the coefficients from the central cylinders of the array showed the identical values. The latter coefficients were, then, normalized with several non-dimensional parameters. The results depicted that the parameters, Ra_G*(G/d) or Ra_G(G/d), well predict the present Nusselt numbers, Nu_G, and their correlation equations were proposed. Moreover, based on the present correlations, optimum spacing to make the Nusselt numbers maximum was discussed.