Numerical simulation and optimization of turbulent nanofluids in a three-dimensional rectangular rib-grooved channel

In this study, numerical simulations by single and two-phase models of nanofluids turbulent forced convection in a three-dimensional rectangular rib-grooved channel with constant wall temperature are investigated. The elliptical, coupled, steady-state, three-dimensional governing partial differential equations for turbulent forced convection of nanofluids are solved numerically using the finite volume approach. The standard k - epsilon turbulence model is applied to solve the turbulent governing equations. The interactive influences of rectangular ribgroove geometrical ratios and nanofluid volume concentration on the average Nusselt number are provided in this study. The average Nusselt number of rib-grooved channel is found to improve more with smaller ribgrooved height ratios, and some ratios of rib-grooved pitch. Furthermore, the numerical results of the single and two-phase models show that there are some differences in simulated flow filed and turbulent convective heat transfer characteristics. In addition, the optimization of this problem is also presented by using the response surface methodology (RSM) and the genetic algorithm method (GA). The objective function E defined as the performance factor has developed a correlation function with four design parameters. It is found that the objective function E is better at Re = 10,000, and rectangular rib-grooved has an 18.2% enhancement. (C) 2015 Elsevier Ltd. All rights reserved.