Magnetized impacts of Cattaneo-Christov double-diffusion models on the time-dependent squeezing flow of Casson fluid: A generalized perspective of Fourier and Fick's laws

Abstract

The characteristics of Cattaneo-Christov heat and mass fluxes in an unsteady two-dimensional squeezing flow of a magneto-hydrodynamic (MHD) Casson fluid between two parallel plates with thermal radiation and Joule dissipation effects under the influence of time-dependent homogenous first-order chemical reaction is examined numerically. Present physical model is analyzed under the influence of Lorentz forces to investigate the effect of a magnetic field on the flow behaviour. Further, the heat generation or absorption concept with chemical reaction is introduced to visualize the heat and mass transfer behaviour under the influence of Cattaneo-Christov heat and mass flux models. The non-Newtonian behaviour of the Casson fluid flow model results in highly nonlinear, coupled, time-dependent partial differential equations and that are reduced to a system of nonlinear ordinary differential equations by using the similarity transformation approach. The numerical methods such as, the Runge-Kutta fourth-order integration scheme with shooting method (RK-SM) and bvp4c techniques are being used to generate the similarity solutions of the governing equations. The convergence between RK-SM and bvp4c techniques is established. The graphical trends of various control parameters concerning to velocity, temperature and concentration fields with skin-friction coefficient, Nusselt and Sherwood numbers are analysed and discussed. The outcomes of the present numerical simulations indicate that the temperature and concentration distributions are fewer in case of the Cattaneo-Christov heat and mass flux models as compared to the classical Fourier's and Fick's laws of heat and mass diffusions. Also it is observed that the magnitude of local heat transfer rate increases with increasing values of heat source/sink parameter. To check the correctness of the current numerical methods, the comparison has been made with the existing results in the literature and excellent agreement was found. © 2019, Società Italiana di Fisica / Springer-Verlag GmbH Germany, part of Springer Nature.