Soret and dufour effects on unsteady non-linear mixed convection flow past a stretching sheet influenced by non-linear thermal radiation

Abstract

This article presents a novel mathematical model to analyze the behavior of a time-dependent, incompressible, non-linear (quadratic) mixed convection flow across a stretching surface heated by convection. The model takes into account the influence of non-linear thermal radiation, along with the Soret and Dufour effects. The equations governing the flow characteristics in the boundary layer approximation are derived and transformed into ordinary differential equations (ODEs) using similarity variables. The second-order ODEs are transformed into an initial value problem, which is then numerically solved using the bvp4c solver in MATLAB. The novel findings of the study have been presented using graphs and tables. The intensification of non-linear convection parameters has been shown to lead to the development of velocity near the sheet while simultaneously reducing velocity toward the free stream. The non-linear convection parameters reduce the temperature distribution, while the temperature ratio and the non-linear thermal radiation parameters enhance it. The non-linear convection parameters ( 0.5 ≤ α 1 , α 2 ≤ 2.0 ) , temperature ratio ( 1.2 ≤ θ w ≤ 1.5 ) , and non-linear thermal radiation ( 1.0 ≤ Rd ≤ 1.5 ) , parameters are influential factors in decreasing the surface drag force (by about 15.4%, 28.5%, 4.4%, and 4.3%) and increasing the cooling rate (by about 0.4%, 0.5%, 19.5%, and 23%), respectively. The Biot ( 0.5 ≤ Bi ≤ 1.0 ) number is also found to significantly contribute toward enhancing the cooling rate of the system by about 51.6%.