外管加熱・内管冷却した水平二重管の配置角度による伝熱特性の変化 : 外管が楕円形状管の場合

抄録

This study was researched by a numerical analysis and experiment, on a natural convection heat transfer in a oriented horizontal elliptical annuli between heated outer tube and cooled inner tube. The outer tube was elliptical tube, and inner tube was cylindrical tube. It was experimented with the outer tube oriented to vertical side, slant upper side 45 degrees, horizontal side, respectively. The numerical analyses were performed by changing the elliptical ratio, inner tube radius, oriented angle, and Rayleigh number as parameters. Results obtained for different conditions are presented as temperature profiles, flow patterns, local Nusselt number, and total heat transfer. It was presented that the heat transfer enhancement effect or heat transfer obstruction effect for the total heat transfer by oriented angle.