熱伝達率の研究 : 突起物を有する外壁面の熱伝達特性に関する風洞実験

Abstract

This paper concerns the relation between the distribution of wind velocity near the surface of a wall and its wall roughness and heat transfer characteristics. A test plate which formed part of a wind tunnel apparatus was used. To make clear the relation between wall roughness and heat transfer coefficient, we attached a fin-like projection to a test plate and examined the distribution of wind velocity, the turbulent intensity and the heat transfer characteristics. We also examined them when the projection is not used, and compared the former values with the latter. The experimental results show 1) that the heat transfer coefficint on the surface of a building wall is influenced by the distribution of wind velocity and the distribution of turbulent intensity, 2) that when a projection is attached to the surface of a wall, three regions, separated, reattached and redevelopment ones, are formed neat the surface of the wall behind the projection, and the heat transfer coefficient indicates different values in these regions, 3) that when a projection is attached to the surface of a wall, the maximum value is found in the reattached region and is 1.5 times as large as that of a wall without the projection.