Modeling heat and mass transfer in Williamson nanofluid stagnation flow: Influence of porosity, chemical reaction, and internal heating

• Heat and mass transfer in Williamson nanofluid. • Similarity transformations reduced governing PDEs to ODEs. • Numerical solutions obtained using MATLAB bvp4c solver. • Concentration decreases with higher Lewis and reaction rates. • Skin friction rises with Williamson, drops with porosity. Stagnation point flow of non-Newtonian fluids is crucial in understanding fluid behaviour in cooling systems, thrust bearings and other applications involving polymers and suspensions. 2,2 The present work explores the heat and mass transfer for stagnation point flow Williamson nanofluid over a porous stretching sheet subject to chemical reaction and internal heating. The partial differential equations governing the flow are formed as per the fundamental laws of heat and mass transfer. These equations are further transformed into ordinary differential equations using similarity transformations. The bvp4c package of MATLAB is used for solving the coupled ordinary differential equations formed. The profiles of velocity, temperature and concentration are graphically studied along with skin friction coefficient, Nusselt number and Sherwood number for varying values of the flow parameters like Williamson parameter(λ: 0.0 − 0.5) and stagnation parameter (ε: 0 − 0.2), porosity parameter ( k 1 : 0 − 1)), heating parameter( s : 0 − 0.2), radiation parameter( R : 0.1 − 0.5), thermophoresis parameter( Nt : 0.1–0.5), Brownian motion parameter( Nb : 0.1 − 0.5),Chemical reaction parameter(γ: 0.2 − 1.0) etc. The significant findings from this study reveal that stagnation parameter enhances velocity profiles while causing a decrease in temperature and concentration values. Nusselt number accelerates with stagnation parameter and radiation parameter. Also, comparative analysis is performed between previously published results and results obtained in this study. 1,2