Homogeneous-heterogeneous reactions in the stagnation-point flow and heat transfer of nanofluids over an exponentially stretching/shrinking sheet with stability analysis

Abstract

This study focuses on the steady two-dimensional stagnation-point flow of nanofluids over an exponentially stretching/shrinking sheet in presence of homogeneous-heterogeneous reactions. Three types of nanoparticles, namely Copper, Alumina and Titania in the water-based fluid with Prandtl number Pr = 6.2 are considered. Similarity transformations are used to transform the partial differential equations into nonlinear ordinary differential equations and are solved numerically using bvp4c solver in Matlab. The influence of various parameters such as solid volume fraction, homogeneous and heterogeneous reaction rate and the stretching/shrinking parameter on the dimensionless velocity, temperature, concentration, skin friction and heat transfer are explored and presented in the form of graphs and interpreted physically. The results indicate that dual solutions exist for an exponentially shrinking sheet. A stability analysis has been performed to show which solutions are stable and physically realizable. Based on the analysis, the results indicate that the first solutions are stable, while the second solutions are unstable.