Temperature Distribution In Layers Research Articles

Experiments of Free-Convection Heat-Transfer from a Vertical Cylinder Submerged in Liquids

Free convection was experimented with two kinds of vertical cylinders (the one was about 12 cm in height and the other was about 35 cm in height) submerged in water or ethylene-glycol. For laminar heat transfer, it was proved that the Ostrach's theoretical solution was right within the equal accuracy of measuring instruments, and that the authors's and Yamagata-Kawano's theoretical treatments were right on selections of physical constants, and of effective values of surface temperature and fluid temperature. For the turbulent heat-transfer, especially the relation between local Nusselt number and local Grashof number could be measured through improvement of the heating device. The following relations were found for ethylene-glycol ; [numerical formula] Similar relations to the above would be obtainable for other fluids. Heat-transfer coefficients of a vortex street zone are little different from these of laminar flow. Boundary layer temperature distributions measured with a thermocouple showed only the characteristics of flow pattern, that is laminar, vortex street, or turbulent.