Abstract

The heat carried off by fluid from a surface, apart from the effect of radiation, is proportional to the internal diffusion of the fluid at and near the surface. The rate of this diffusion depends first on the nature of the fluid and secondly on the effect of eddies which arises entirely from the motion of the fluid and is proportional both to the density of the fluid and the velocity with which it flows past the surface. Using the apparatns shown in the figure, we investigated the heat transmission between water through the condenser tube wall and verified Reynolds' law of heat transmission. It was also shown that the twisted retarder inserted in the cooling water passage substantially improved the transmission of heat. Moreover a phenomena which was supposed to be the effect of the critical velocity was observed in the experiment.