Natural convection of Water/MWCNT nanofluid flow in an enclosure for investigation of the first and second laws of thermodynamics

Abstract

This study deals with the numerical simulation in the case of natural convection of nanofluid flow within a semi-circular enclosure for the cooling of a silicon chip. Water/MWCNT nanofluid is included in cooling fluid in the volume fraction of nanoparticles 0 ≤ φ ≤ 6%. In this numerical study, natural convection of nanofluid flow is performed inside a semi-circular enclosure for cooling of an electronic chip using the Finite Volume Method (FVM). In this study, flow is simulated for Ra = 1 × 105, 1 × 106, 1 × 107, and 1 × 108. The findings confirm that increasing the Rayleigh number leads to the augmentation of the driver of fluid vortexes. Fluid motion with a higher route length (larger attack angle) leads to the intensity of flow domain motion which this intensity is more considerable by augmenting the Rayleigh number. The enhancement of attack angle regarding enclosure leads to strong fluid circulation and better flow rotation. The highest heat transfer distribution is seen in φ = 6% which in Ra = 1 × 108, it is more sensitive compared to Ra = 1 × 105. At the flow separation regions between two vortexes, the temperature increments due to the creation of an intermediate region. As the Rayleigh number is increased, due to the augmentation of fluid circulation, flow motion intensity goes up e and the separation regions of vortexes lead to strong changes in the friction factor graphs. The highest friction factor is created where fluid motion components are with higher changes or significant effects in the instance of the boundary layer of flow representing themselves in these regions. The created difference between the two sides of the Nusselt number graphs is due to the attack angle changes. The values of velocity and temperature gradients are the factors that lead to the increase of entropy.