The problem of turbulent boundary layer separation due to adverse pressure gradient is an important factor in the design of many devices such as jet engines, airfoils, rocket nozzles, and helicopter blades and the design of many fluidic logic systems. As a result, wind tunnel experiments were conducted to investigate the separation developing on a flat-plate in steady and unsteady flow. The nature of upstream flow subjected to the effect of unsteady free stream velocity which changes sinusoidally with time due to the rotation of an elliptical cylinder placed downstream of the flat-plate has been studied in the wind tunnel test section.