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Synthetic jet actuators (SJAs) are devices that control fluid flow by synthesizing surrounding fluid without altering the flow from the cavity. Before optimization, the selected diaphragm frequencies are subjected to a CFD solution using a dynamic mesh. Output parameters of selected loudspeaker-driven SJA are optimized under quiescent conditions. Comparisons are made between the best optimization candidate design point, experimental reference, and baseline CFD study before optimization. Re increases by 17% at 50Hz and 8.7% at other frequencies. St decreases by almost 30% across all frequencies. $L$ is maximized and held over 4. Optimized design, based on response surface model, demonstrated a consistent ability to produce higher, more centralized velocity profiles.

Synthetic Jet Actuator (SJA) works cyclically with the directionally transportation of fluid near the exit, and the paper presents the performance of a loudspeaker driven SJA in static flow field. Time-Resolved Particle Image Velocimetry (TR-PIV) system is used to measure the flow field characteristics near the SJA slot exit with input voltage changing, and the flow field snapshots obtained by TR-PIV are modality analyzed by Dynamic Mode Decomposition (DMD) method. The PIV experiments show that by varying input voltage at fixed oscillating frequency, the loudspeaker diaphragm vibration displacement is the parameter that affects the jet velocity and the performance of the SJA. The traveling vortex vanishes at high voltage due to the interaction between vortex structures and the synthetic main jet. In DMD method, the first three-order modes can characterize the main information of the original flow field with reverting the flow field snapshot sequence. It indicates that the DMD method is applicable in the SJA flow field research and the reduced order model can effectively simplify the analysis of flow field.