Numerical modeling of nanofluid flow and heat transfer in a quartered gearwheel-shaped heat exchanger using FVM

Abstract

The numerical modeling of natural convection fluid flow and heat transfer in a quarter of gearwheel-shaped heat exchanger is carried out. The heat exchanger is included with internal active square bodies. These bodies have hot and cold temperatures with different thermal arrangements. Three different thermal arrangements are considered and showed with Case A, Case B and Case C. The CuO-water nanofluid is selected as operating fluid. The Koo-Kleinstreuer-Li (KKL) correlation is utilized to estimate the dynamic viscosity and thermal conductivity. In addition, the shapes of nanoparticles are taken account in the analysis. The Rayleigh number, nanoparticle concentration and thermal arrangements of internal active bodies are the governing parameters. The impacts of these parameters on the fluid flow, heat transfer rate, local and total entropy generation and heatlines are studied, comprehensively. The results show that the heat transfer rate enhances with increasing of Rayleigh number and nanoparticle concentration. Moreover, the thermal arrangement of internal active bodies has considerable effect on the heat transfer between heat sources and heat sinks. On the other hand, the total entropy generation enhances and decreases with increasing of Rayleigh number and nanoparticle concentration, respectively.