Flow-induced oscillation of free reeds

We present an investigation of the mechanism by which air flow induces oscillation in free reeds, which produce sound in several musical instruments. In this system, a thin strip of metal is clamped at one end to the top of a plate above a slot large enough for it to pass through. This geometry allows a uniform flow to induce and sustain large-amplitude oscillations of the reed. We investigate experimentally the conditions under which oscillation occurs and formulate a theoretical model, informed by the work of St. Hilaire et al. [JFM, 1971], to explain our observations.