Several aspects of flow separation control on the modified Glauert's Laminar Airfoil Section 11 (GLAS 11) were investigated experimentally. The control, via zero-net mass flux oscillatory blowing from a spanwise slot was considered. The present investigation attempts to quantify the control efficacy of the method and to study the dynamical effects of reattachment and separation, as a prerequisite for closed-loop control. The possible mechanisms of the control and their effect on the flow dynamics are discussed. The significance of the ramp curvature was also of concern. Since the control of the separation over a wall-mounted hump, having a shape that is similar to the upper loft of the GLAS II airfoil, was extensively investigated recently, the present experiment focuses on the differences between the flow over such a hump and over an airfoil. A temporal response of the flow to changes in actuation is considered as well.