Mixed convection of Casson fluid in a differentially heated bottom wavy wall

Abstract

Numerical simulations of mixed convection of Casson fluid with a heated bottom wavy wall in a trapezoidal enclosure are performed. The enclosure's left and right sidewalls are assumed to be cold temperatures, while the enclosure's bottom and top walls are kept at hot temperatures and thermally insulated, respectively. The top wall is supposed to slide at a constant speed U0 from left to right. After transforming the governing equations into a non-dimensional form, the finite element method is employed to solve them and modeled with Comsol-Multiphysics. The effect of non-dimensional parameters such as the Richardson number (Ri=0.1,1,10), Casson fluid parameters (ϕ=0.1,0.5,1), and the number of oscillations (N=0,1,2,3) on flow and thermal fields, as well as the heat transfer rate has been studied. Furthermore, the results for the Average Nusselt number over the heated bottom wavy wall under the influence of the Rayleigh number and Casson parameter are depicted. The results showed that as the Richardson number increases, so does the average Nusselt number for all Casson fluid parameter values.