International Journal of Thermofluids (Nov 2024)
Exploring the efficiency of employing Fe3O4-MWCNT Nanofluids in a heat sink equipped with circular micro pin-fins
Abstract
This work investigates the effects of adding different turbulence-inducing elements and varying the concentration of Fe3O4-MWCNT hybrid nanofluid to evaluate the efficiency of a micro pin-fin heat sink. To achieve this objective, a multiphase Lagrangian-Eulerian method that includes gravity, thermophoresis, drag force, Saffman lift, virtual mass, and pressure gradient-induced force to model will employ hybrid nanofluids. The evaluation of heat sink efficiency includes the analysis of quantitative variables like surface Nusselt number, average Nusselt number, and the logarithmic mean temperature difference. Furthermore, a qualitative representation of flow and thermal distributions is illustrated by visualizing flow streamlines, vortex contours, and thermal contours. This topic is addressed in the current work by using the finite volume approach with Ansys Fluent 18.1. Using the multiphase Lagrangian-Eulerian approach, the hydrothermal performance of the Fe3O4-MWCNT hybrid nanofluid in a pin-fin heat sink is investigated. This article's novelty lies in its utilization of four distinct turbulator models, each with unique geometries and widths. These models are positioned within a heat sink with micro fins and are tested in the presence of Fe3O4-MWCNT nanofluids. According to the findings, using the hybrid nanofluid at a concentration of 5 % rather than 1 % causes an average Nusselt number rise of 7.3 %, 9.4 %, and 12.5 % in various heat sink segments. This study's most significant thermal enhancement is associated with case D, which demonstrated a 7 % improvement over the baseline scenario by employing Fe3O4-MWCNT at a concentration of 5 % and a Reynolds number of 2400. It has been demonstrated that hybrid nanofluids have thermal efficiency between 600 and 2400 Reynolds numbers. The thermal efficiency criteria represent the base model, denoted by η = 1. A higher thermal efficiency denotes a more cost-effective design that offers superior heat transmission at a reduced pressure drop. It has been discovered that raising the concentration of hybrid nanofluids improves the micro pin fin heat sink's thermal performance by increasing the heat transfer coefficient.
