Estudo da influência da umidade relativa no coeficiente convectivo: análise de escoamento cruzado em cilindro

Abstract

The present paper brings an analysis of the influence of relative humidity on convective coefficient. Theoretical/experimental studies were conducted on a cylindrical metallic resistance internally heated by Joule effect, subjected to a cross-flow of an air-steam mixture in a psychrometric tunnel, to allow heat transfer by convection from the cylindrical resistance’s surface to the fluid. By varying cylinder temperature, air velocity and relative humidity, it was possible to calculate the convective coefficient both experimentally, by using Newton’s Cooling Law, as such as theoretically, by using the correlations found at specialized literature. By using the same correlations, it was also possible to calculate the convective coefficient for dry air, at the same temperatures, aiming to analyze the influence of the relative humidity of the air at the heat transfer. Once the comparisons among the convective coefficients were finished, the conclusion was that the relative humidity did interfere in thermal exchanges between the cylindrical resistance and the fluid.