A Study on the Heat Transmitting Phenomena When Heated Gas flows across the Periphery of Heat Transmitting Tubes

Abstract

The heat transmitting phenomena caused around the periphery of heat transmitting tubes when heated gas flows across the tubes were measured at various gas speeds as well as in various tube arrangements, and also the variation of gas temperature around the heat transmitting tubes was measured. From the results of the measurements, it was investigated that the heat transmitting phenomena at the outer surface of the tubes is mainly governed by the cooling layers produced around the periphery and it was possible to judge under what conditions the coolinx lavers will be attached around the circumference of the tubes. If properties of gas, diameters of tubes and the surface condition of tubes are considered constant, the generation of the cooling layers i.e. the conditions of governing the heat transmitting phenomena comprise two elements of the speed of gas and the arrangement of tubes. In the Present experiments, the relations of various factors within the above mentioned range of variations were minutely measured and it was possible to clarify the fundamental relations which are necessary for the determination of the arrangement of heat transmitting tubes.