Homotopy analysis method with application to thin-film flow of couple stress fluid through a vertical cylinder

This work solves the problem of thin-film withdrawal and drainage of a steady incompressible couple stress fluid on the outer surface of a vertical cylinder. The governing equations for velocity and temperature distributions are subjected to the boundary conditions and solved with the help of homotopy analysis method. The obtained expressions for flow profile, temperature profile, average velocity, volume flow rate, and shear stress confirmed that the thin-film flow of couple stress fluid highly depends on involved parameters say Stokes number S-t , vorticity parameter lambda, couple stress parameter eta, and Brinkman number Br presented in the graphical description as well.