Analytical Solution of MHD Stagnation-Point Flow and Heat Transfer of Casson Fluid over a Stretching Sheet with Partial Slip

This paper investigates the hydromagnetic boundary layer flow and heat transfer of a non-Newtonian Casson fluid in the neighborhood of a stagnation point over a stretching surface in the presence of velocity and thermal slips at the boundary. The governing partial differential equations are transformed into nonlinear ordinary differential equations using similarity transformations. The analytic solutions are developed by a homotopy analysis method (HAM). The results pertaining to the present study indicate that the flow and temperature fields are significantly influenced by Casson parameter ( ), the magnetic parameter , the velocity slip parameter , and the thermal slip parameter . An increase in the velocity slip parameter causes decrease in the flow velocity, while an increase in the value of the thermal slip parameter causes increase in the temperature of the fluid. It is also observed that the velocity at a point decreases with increase in . 1. Introduction The problems of flow and heat transfer in the boundary layer adjacent to a continuous moving surface have received great attention during the last decades owing to the abundance of practical applications in chemical and manufacturing processes, such as polymer extrusion, continuous casting of metals, glass fibre production, hot rolling of paper, and wire drawing. Sakiadis [1] was the first, among others, to investigate the flow behavior on continuous solid surface. Thereafter, numerous investigations were made on the flow and heat transfer over a stretching surface in different directions [2–8]. All the previous researchers restricted their analyses to flow and heat transfer for the Newtonian fluid. In recent years, it has been observed that a number of industrial fluids such as molten plastics, polymeric liquids, blood, food stuff, and slurries exhibit non-Newtonian fluid behavior. Different types of non-Newtonian fluids are viscoelastic fluid, couple stress fluid, micropolar fluid, power-law fluid, Casson fluid, and many others. Rajagopal et al. [9] and Siddappa and Abel [10] studied the flow of a viscoelastic fluid over a linear stretching sheet. Troy et al. [11], Lawrence and Rao [12], and McLeod and Rajagopal [13] discussed the problem of uniqueness/nonuniqueness of the flow of a non-Newtonian viscoelastic fluid over a stretching sheet. Rajagopal et al. [9] analyzed the solutions for the flow of viscoelastic fluid over a stretching sheet. This study was further generalized to investigate the flow of short memory fluid of type Walter's liquid B by several authors, such as Andersson [14],