Numerical Investigation of Free and Forced Convection Heat Transfer of Nanofluid in Inclined Tubes

In this paper, free and forced convection heat transfer of nanofluids in inclined tubes for laminar flow are investigated. Nanofluid is used in various industries such as automobiles, electronics, air conditioning and renewable energies. For simulation, we used a ۲m long and ۰.۰۰۴m diameter ۲D tube which is exposed to a constant heat flux in the outer wall of the tube. We considered the fluid flow to be reversed and investigated the effects of parameters such as inclination angle ۳۰°≤𝜃≤۶۰°, nanoparticle volume fraction ۱%≤𝜑≤۵%, nanoparticle type, Reynolds number ۴۰۰≤𝑅𝑒≤۱۹۸۰ and Grashof number ۷۵۰≤𝐺𝑟≤۷۵۰۰ on heat transfer and pressure drop; For this purpose, we used Ansys Fluent software and solved it numerically. According to the results, it was found that the temperature and velocity of the tube's center line in free convection, unlike forced convection, depends on the inclination angle, and on the other hand, the rate of forced convection heat transfer exhibits an inverse correlation with the increasing Reynolds number. It is worth noting that the pressure drop in natural convection increases with the rise in inclination angle and Grashof number.

کلیدواژه ها:

Nanofluid ، laminar ، convection ، inclination angle ، volume fraction