A novel investigation of Casson fluid flow over an infinite plate with constant temperature by constructing the absorbing boundary conditions

Abstract

Casson fluid has been widely used in blood, honey, chocolate, and various polymer fluids, for which the investigation of its underlying flow and heat transfer mechanisms in complex environments is of vital significance. In this paper, the Casson fluid flow over an infinite moving plate with constant temperature is studied, which leads to a coupled system of the velocity and temperature fields. To treat the infinite coupled system more accurately, the artificial boundary conditions in terms of fractional derivatives are developed using the Laplace transform, which transfers the problem in the infinite domain to a model in the bounded domain. The finite difference method is applied to solve the new bounded coupled system. Furthermore, three numerical experiments are presented to demonstrate the validity and accuracy of the transferred model and the numerical scheme. The influence of some important physical parameters on the velocity and temperature fields is also explored. The main findings are that the viscosity of the Casson fluid decreases with an increasing Grashof number leading to an accelerated flow, the thermal conductivity diminishes as the Prandtl number increases resulting in a weakened thermal effect within the flow, and the velocity at the fixed position decreases as the Casson parameter increases.