本研究針對電磁驅動及壓電驅動之合成噴流，以實驗方法研究合成噴流出口的速度震盪特性、流場特徵衍化及速度場。電磁驅動的合成噴流的出口型式分別為圓噴流、槽噴流及矩陣噴流，每一種出口型式的電磁驅動的合成噴流均有三種不同的出口面積。利用雷射輔助流場可視化技術觀察動態流動模態；藉由熱線風速儀量測合成噴流出口處以及中心線的軸向速度變化以及震盪頻率。結果顯示，在共振頻率時，噴流出口會產生最大的速度震盪。在相同出口截面積以及震盪頻率時，速度震盪的振幅，以圓噴流型式之電磁驅動的合成噴流最大，槽噴流居中，矩陣噴流最小。對同一種出口型式的電磁驅動的合成噴流而言，出口截面積越小，速度震盪的振幅值越大。合成噴流的出口產生速度震盪，因此噴流出口流場為持續性的渦漩結構。當渦漩結構往下游移動時，捲入週圍的靜止空氣，因此渦漩結構尺寸變大並且變形。另外，應用質點影像測速儀(PIV)取出合成噴流出口流場結構的全域速度場，分析與探討合成噴流出口處的速度向量場、流線圖及等速度分佈輪廓。

The instantaneous and averaged flow patterns and velocity fields of the electromagnetically and piezoelectrically driven synthetic jets were experimentally investigated. The exit configurations of the electromagnetic synthetic jets were circule, slot, and multi-circle. For each exit configuration, three exit areas, 3.14, 7.07, and 12.56 mm2, were used. The hot-wire anemometer was employed to measure the time-varying velocities at the jet exits and along the centerline. Jet oscillation frequencies were obtained by using the fast Fourier Transform (FFT) analysis technique. The laser-light shhet assisted flow visualization technique was used to understand the evolution proves of the flow patterns. The results of hotwie measurement showed that the oscillation amplitudes at the resonance frequency attained the maximum values. At the same exit cross-section areas and driven frequency, the velocity oscillation amplitudes at the circular-jet and the multijet exits presented the highest and the lowest values, respectively, among the three configurations. The vortical strucures evolved periodically because of velocity oscillation at exit of the synthetic jets. The vertical structures entrained the environment fluid as it travels downstream so that the vertical structure enlarged and deformed. Adittionally, the velocity fields around the jet exit of the synthetic jets were quantified by employing the particle image velocimeter. The velocity vectors, streamline patterns, and velocity contours of various synthetic jets were presented and

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