In one embodiment, the present invention provides an apparatus for creating pulsating fluid flow, including an inlet into which fluid flows and a chamber having an upstream end and a downstream end. The chamber is defined by a pair of outwardly-projecting sidewalls, and the inlet is disposed at the upstream end of the chamber. This particular embodiment further includes at least two feedback passages with opposed entrances at the downstream end of the chamber and opposed exits at the upstream end of the chamber, near where the chamber joins the inlet. At least one feedback outlet leaves each of the feedback passages. A feedback cavity is disposed at the downstream end of the chamber. At least one exit flowline having an exit port leaves the at least one feedback outlet.