Control of a Round Jet Intermittency and Transition to Turbulence by Means of an Annular Synthetic Jet

This paper deals with active control of a continuous jet issuing from long pipe nozzle by means concentrically placed annular synthetic jet. The experiments in air cover regimes laminar, transitional, and turbulent main flows (Reynolds number ranges 1082–5181). velocity profiles (time-mean fluctuation components) unforced forced jets were measured using hot-wire anemometry. Six flow are distinguished, their parameter map is proposed. possibility turbulence reduction forcing transitional demonstrated, the maximal effect revealed at Re = 2555, where ratio intensities decreased up to 0.45.