Abstract
In this study, the horizontal temperature distribution on a heated disc in a cyrindrical flow channel has been measured to undestand heat transfer in the chemical vapor deposition reactor. For air gas flow, the time course of temperature had both regular and irregular oscillation because of natural convection. The more the distance between the gas inlet and the heated disc made the more the amplitude of the oscilation. This tendency became more remarkable at the edge of the disc because the rotation speed of natural convection could increase with the distance. On the other hand, for hydrogen gas flow, the temperature at all positions was at almost steady state and higher than that for air flow. The reason would be why the Peclet number for the hydrogen was much less than that for air. For Rayleigh number Ra < 500000, the average Nusselt number Nuav was almost 5 independently of Reynolds number and kind of gas. On the other hand, for Ra > 500000, Nuav increased dramatically and approached to about 11. It was predicted that the growth rate at the edge of the disc could be greater than that at the center in these experimental conditions.
