DefinePK

Abstract

Turbulent flow and heat transfer in tubes are among the most important issues in almost all industries. This paper aims to numerically analyze forced convective heat transfer within the tube. To this end, the fluid flow in the tube is considered as turbulent together with heat flux along the entire surface of the tube. In this article, the Reynolds number varies in a range of 5273-20, 000. Also, the Prandtl number (Pr) is considered equal to 0.7 and 4 for the target fluid. A non-uniform three-dimensional network along with Spalart-Allmaras turbulence model is used for modeling and simulation of the fluid flow and heat transfer. The length of the tube used in this study is 25 times of its diameter. In this study, after reviewing the validity of the results, changes in the fluid temperature inside the tube are investigated based on the distance from the tube wall and along the length of the tube. Moreover, the tube surface temperature is studied for flows with different Reynolds numbers. Results show that the mean tube surface temperature decreases by increasing the value of the Reynolds number, whereas it increases by increasing the Prandtl number. Moreover, it is observed that, with increasing the Prandtl number, the tube surface temperature is more quickly stabilized.