M. S. Dada et al. 175 Unsteady Non-Newtonian Magnetohydrodynamic Radiative Thin Film Flow in a Porous Medium Past an Oscillating Vertical Belt M.S. Dada*, L. Yakub, A.S. Adeyemo Department of Mathematics, University of Ilorin, Ilorin Nigeria. Corresponding author: dadamsa@gmail.com Abstract This study examines the unsteady non-Newtonian magnetohydrodynamic radiative thin film flow in a porous medium past an oscillating vertical belt. Based on the physical model of the problem, the governing momentum and energy equations are non dimensionalized and solved analytically using Optimal Homotopy Asymptotic Method (OHAM). The velocity and temperature profiles are studied for different physical parameters such as the magnetic field, radiation parameter, Grashof number, Prandtl number, and Brinkman number for both lift and drainage problems. The analytical results are presented graphically and discussed. Keywords: OHAM, Thin film, Unsteady, Second grade fluid, Buoyancy, Viscous dissipation. Introduction The study of non-Newtonian fluids of thin film flow has aroused the interest of researchers and received considerable attention because of its numerous applications in various branches of science, engineering and technology: particularly in chemical and nuclear industries, material processing, geophysics and bio-engineering. The importance of non- Newtonian fluid flow especially in a porous medium has led to the development of mathematical models in an extensive range. Its areas of application include petrochemical, bio-medical and environmental engineering such as polypropylene coalescence sintering, blood, geological and debris flows. http//www.unilorin.edu.ng/centrepoin t Volume 24, No.2, pages 175-196 ©2018 University of Ilorin Centrepoint Journal (Science Edition) 2141-3819/2017 $5.00 + 0.00 CPJ 2018023/24211