Two-dimensional and axisymmetric unsteady flows due to normally expanding or contracting parallel plates

The flow of a viscous incompressible fluid between two parallel plates due to the normal motion of the plates for two cases,the two-dimensional flow case and the axisymmetric flow case,is investigated. the governing nonlinear equations and their associated boundary conditions are transformed into a highly non-linear ordinary differential equation. the series solution of the problem is obtained by utilizing the homotopy perturbation method (hpm). graphical results are presented to investigate the influence of the squeeze number on the velocity,skin friction,and pressure gradient. the validity of our solutions is verified by the numerical results obtained by shooting method,coupled with runge-kutta scheme. © 2012 saeed dinarvand and abed moradi.