Abstract: A method and mechanism of producing a suction and periodic excitation flow. The method includes providing fluid flow from jet port with diameter dl at a controlled input pressure (Pin), directing the flow to a conduit with diameter d2, >d1, allowing additional fluid to join the flow through suction slot(s) to create an amplified flow in the conduit, further directing the amplified flow in a first direction by applying a transverse pressure differential, further redirecting the amplified flow in another direction by modifying an angle by which the transverse pressure differential is applied and iteratively repeating the further directing and further redirecting so that the amplified flow oscillates between the directions. The suction and periodic excitation flows may be employed, for example, to effectively control boundary layer separation. A mechanism for automated performance of the method is also disclosed.