Recirculation Flow of Nanofluid Through Periodic Nanotube with Hexagonal Cross-Section

Abstract

In this paper, we have investigated the recirculation flow of a nanofluid in the developed flow zones of an infinite periodic nanotube with a hexagonal cross-section. A numerical analysis is commenced to identify the existence of single and double recirculation zones for various geometric parameters. The boundary element method (BEM) has been formulated for an unbound interim nanotube for solving the governing equations. We have developed the codes for the BEM method in FORTRAN 90, and the graphs have been plotted in MATLAB 2016. We have various geometric parameters to inaugurate circumstances for the onset of recirculation. We have found recirculation flow through this type of periodic tube for a set of geometric parameters such as amplitude, wavelength and throat radius etc. Firstly recirculation flow in the expansion region of the nanotube is prophesied to arrive beyond a critical amplitude and second order recirculation zone is also predicted for still higher amplitudes. The recirculation flow has great importance in the application, for example, it can be used in the particle separation process.