Diffusion of dual diffusive chemically reactive Casson nanofluid under Darcy–Forchheimer porosity and Robin conditions from a vertical convective surface: a comparative analysis using HAM and collocation procedures

This investigation reports Casson liquid stretching flow persuaded by convectively heated permeable surface. Porous medium effects under Darcy–Forchheimer relation are scrutinized. Nonlinear version of thermo-solutal buoyant forces (i.e., nonlinear mixed convection) is introduced. Nanoliquid model features thermophoresis and Brownian diffusions. Characteristics of heat transfer are elaborated considering heat absorption, thermal radiation, Robin conditions and heat generation. Mass transfer effects are addressed considering chemical reaction. Similarity approach assists to simplify governing expressions (partial differential equations) into the ordinary ones, and these ordinary differential expressions are tackled analytically (via homotopy analysis scheme) and numerically (via bvp4c scheme). The obtained results via homotopy and bvp4c methods are also validated. Besides, the consequence of multiple emerging parameters on dimensionless profiles is investigated via graphs and tables. It is scrutinized that velocity is strongly enhanced with increasing nonlinear mixed convection parameter while it diminishes with increasing Casson fluid parameter, inertia coefficient parameter and porosity parameter.