On series solution for unsteady boundary layer equations in a special third grade fluid

Analytic solution for the time-dependent boundary layer flow over a moving porous surface is derived by using homotopy analysis method (HAM). A special third grade fluid model has been used in the problem formulation. The obtained HAM solution is also compared with the numerical solution and a reasonable agreement is noted.

Research highlights► Unsteady boundary layer flow of a special third grade fluid are considered by HAM. ► The boundary layer thickness is an increasing function of third grade parameter. ► Boundary layer thickness in injection is larger than suction. ► HAM applied for large values of a non-Newtonian parameter in injection/suction cases.