摘要

In this work, the effect of pipeline surface paint color on development of horizontal pipe flow temperature is investigated numerically. The classical pipe flow problem with constant wall heat flux is presented in which thermal leakage to the ambient from the outer surface of the pipe flow by convection and radiation is taken into account. The effects of emissivity and absorptivity of the pipe surface on temperature profiles of both the fluid and pipe surfaces have been studied numerically. The results show that the bulk temperature tends to a limiting value (i.e., does not rise linearly as in the classical constant heat flux problem). It is found that emissivity and absorptivity of the outer surface of the pipe are significant parameters in the development of pipe flow temperature which can either increase or decrease the pipe surface and fluid temperatures. Furthermore, it can be concluded that the friction factor and pressure drop are mainly affected by absorptivity and emissivity of the outer pipe surface.