Effectiveness of activation energy on Casson nanofluid flow between two exothermic chemically reactive orthogonally moving disks

Abstract The objective of this study is to address the time-dependent movement of thermally radiative Casson nanofluid between two orthogonally moving disks. The Buongiorno nanofluid model is used to address the critical nanoparticle transport mechanisms, specifically Brownian movement and thermophoretic, which play a major contribution in affecting heat and solutal transfer properties. The modeled equations are transformed into a framework of non-linear ordinary differential equations by employing suitable similarity transformations and then solved using the bvp4c solver. The key outcomes reflected that an increment in the thermophoresis factor improves the fluid temperature but reduces the Nusselt number. A higher Brownian motion boosts both the nanoparticle concentration and Sherwood number. A greater activation energy leads to a temperature drop but an increase in concentration, whereas a higher reaction rate diminishes the concentration. When the thermophoresis parameter values ranged from 0 to 2, the heat transfer rate dropped by 31.87 %. The mass transfer rate reduced by 16.03 % when the activation energy constraint values are between 0 and 3. The numerical results are validated using a Bayesian neural network, which showed good agreement with the bvp4c solutions, with a mean squared error on the order of 10 −9 .