Towards understanding thermal management in unsteady boundary layer flow with AC/DC electric fields

Abstract

Unsteady boundary layer flow induced by alternating current (AC) or direct current (DC) electric field through a porous layer is investigated numerically. The finite difference method based on Crank-Nicolson is applied to solve the nonlinear system. The governing equations are built with fractional shear stress and the Cattaneo heat flux model, and time fractional derivatives are computed using the Caputo fractional derivative. The numerical results are presented to demonstrate the effects of varying parameters on momentum and thermal boundary layer. The results reveal that the time delay in the velocity profile occurs for larger values of both the velocity fractional derivative parameter and the velocity relaxation time due to the molecules colliding and interacting, thereby exchanging momentum to achieve a new equilibrium. Additionally, factors such as permeability, magnetic field strength (Hartmann number), Grashof number, and Biot number are shown to significantly influence fluid movement, heat convection, and temperature gradients within the boundary layer. This insight is of paramount importance in engineering applications such as enhanced oil recovery, geothermal reservoir management, and advanced cooling systems, where precise control of fluid dynamics and heat transfer is essential for optimizing performance and resource utilization.