Convective heat and mass transfer analysis on Casson nanofluid flow over an inclined permeable expanding surface with modified heat flux and activation energy

Abstract

Due to the enormous advantages of nanofluid technology, the study of various nanofluid flows under different assumptions became an important research topic. Furthermore, Fourier proposed the basic heat flux law, and it has some initial disturbances. Later, Cattaneo and Christov modified the Fourier model by including the relaxation term and rectified the conflicts in the Fourier model. Current research explores the influence of activation energy on a chemically reactive Casson nanofluid over a stretching surface. Cattaneo–Christov heat and mass flux are considered for the investigation. The governing PDEs (partial differential equations) along with the boundary constraints are transformed into ODEs (ordinary differential equations) with the aid of suitable similarity variables and then solved numerically by the bvp5c MATLAB package. We have drawn the velocity, temperature, and concentration profiles. Also, plotted the isotherms and streamlines, and analyzed the effects of all the influential parameters on the flow regime. The increasing Casson fluid parameter leads to a decrease in the fluid velocity. Larger value of the Casson fluid parameter (β→∞) recovers the results for the Newtonian fluid. The results obtained from the study show that the temperature shoots up for intensifying values of the magnetic parameter, radiation parameter, Eckert number, thermal Biot number, Brownian motion parameter, and the thermophoresis parameter; meanwhile the increase in the thermal relaxation parameter drops the temperature. The positive values of the heat source parameter decreases the rate of heat transfer by 10%. Also, we noticed that the effect of the growing values of the Schmidt number and the chemical reaction parameter is to decrease the concentration field. Moreover, a rise in the Reynolds and Brinkmann numbers pushes up the entropy generation.