Performance and efficiency of loudspeaker driven synthetic jet actuator

The paper presents the results of a detailed experimental investigation wherein the efficiency of synthetic jet actuator, momentum velocity, Reynolds number and input power as a function of oscillating actuator frequency and for different cavity configuration are studied. Synthetic jet actuator consists of plexiglas cavity and a loudspeaker. We have proposed synthetic jet actuator efficiency definition as a ratio of flow kinetic power based on momentum velocity to electrical power feeding generator. The maximum achieved efficiency is about 5%, although with another loudspeaker the efficiency would be different. Experimental investigation was carried out for the Reynolds number in range Re = 0-22,600 and for the Stokes number St = 13-308. We find out that the maximum efficiency appears close to resonant loudspeaker frequency or Helmholtz frequency. It depends on geometrical configuration of the actuator. Presented results may be useful for designing loudspeaker driven synthetic jet actuator.