In an Annulus, Mixed Convection of Hybrid Nanofluids

Abstract

This work used the Galerkin weighted residual finite element method to investigate mixed convection
in an annulus filled with hybrid nanofluids and produced by two horizontal isothermal cylinder surfaces. The
inner cylinder remains motionless while the outer cylinder rotates. The effects of the solid volume fractions of
various nanoparticles (alumina, copper, and hybrid particles between 0 and 0.02), the inner cylinder's eccentricity,
the outer cylinder's angular rotational speed, and the Rayleigh number on the fluid flow and heat transfer
properties were examined. Average heat transmission was shown to decrease as the outer cylinder's angular
rotating speed increased and to increase with Rayleigh number, solid volume fractions of nanoparticles, and
eccentricity ratio. It was discovered that adding nanoparticles was beneficial for higher angular rotational speed
values and lower Rayleigh number values. When the inner cylinder center moves in a +y direction, the average
Nusselt number rises by 31.75% at the maximum volume percentage of Cu nanoparticles. For the same volume
fraction, heat transfer rates from a hybrid nanofluid including nanoparticles are lower than those from copper
nanoparticles and higher than those from alumina.