Unsteady MHD Boundary Layer Flow and Heat Transfer of a Casson Fluid Past a Stretching Sheet

An analysis is presented to investigate the unsteadyMHD boundary layer flow of a Casson fluid over a stretching sheet for special distributions of the stretching velocity and surface temperature or surface heat flux. The governing partial differential equations have been transformed by a similarity transformation into a system of ordinary differential equations, which are solved numerically using MATLAB solver bvp4c. The flow features and heat transfer characteristics for different values of the governing parameters viz. unsteadiness parameter, Casson parameter magnetic parameter and Prandtl number are analysed and discussed in detail. In the absence of magnetic field, the results obtained reduce to corresponding ones of Swati Mukhopadhyay et al. [35]. Fluid velocity initially decreases with increasing unsteadiness parameter and temperature decreases significantly due to unsteadiness. The effect of increasing values of the Casson parameter is to suppress the velocity field. But the temperature is enhanced with increasing Casson parameter. Fluid velocity decreases with increasing magnetic parameter for both steady 0Aand unsteady 0Acases.