Heat transfer and nanofluid flow characteristics through a circular tube fitted with helical tape inserts

摘要

Numerical investigations are conducted using finite volume method of study the laminar convective heat transfer and nanofluids flows through a circular tube fitted with helical tape insert. The continuity, momentum and energy equations are discretized and the SIMPLE algorithm scheme is applied to link the pressure and velocity fields inside the domain for plain tube and four different twist ratios of 1.954.89, two different types of nanoparticles, Al2O3 and SiO2 with different nanoparticle shapes of spherical, cylindrical and platelets, 0.5-2.0 % volume fraction in base fluid (water) and nanoparticle diameter of 20-50 nm. The wall of tube was maintained at uniform heat flux. In this project, several parameters such as boundary condition (different Reynolds number), types of fluids (base fluid with different type of nanoparticles), different nanoparticle shapes, different volume fraction and different particle diameter are investigated to identify their effect on the heat transfer and fluid flow through a circular tube fitted with helical tape insert geometries. The numerical results indicate that the four types of Nanofluid achieved higher Nusselt number than pure water. Nanofluid with Al2O3 particle achieved the highest Nusselt number. For all the cases Nusselt number increased with the increase of Reynolds number and Nusselt number will increase through a circular tube fitted with helical tape insert with decrease of twist ratio.