Optimization of mixed convection heat transfer with entropy generation in a wavy surface square lid-driven cavity by means of Taguchi approach

The optimum conditions of the mixed convection heat transfer in a wavy surface square cavity filled with Cu-water nanofluid by utilizing the Taguchi method is presented. The governing equations are first discretized by applying a finite volume method and then solved using SIMPLE algorithm. In the Taguchi method, the performance parameter is assumed to be the Nusselt number on the wavy surface. An L16 (43) orthogonal array is considered as an experimental plan for the design parameters. Also, the entropy generation on the wavy surface is examined. The effects of sundry parameter such as the volume fraction of Cu particles, the Nusselt number and the wavelength of the wavy surface on the flow and temperature fields are investigated. It is found that, in a given Richardson number, increasing of the wavelength of the wavy surface decreases the mean Nusselt number and the entropy generation. It is also observed that the case with Ф = 2% and λ = 0.25 at the Richardson number of 0.01 is the optimum design for the heat transfer. The analysis of the Taguchi method leads the optimization process to achieve the maximum Nusselt number (maximum heat transfer) for the designed wavy surface square cavity.