A novel fluidic oscillator incorporating step-shaped attachment walls

A novel fluidic oscillator incorporating step-shaped attachment walls and acute-angle splitters has been designed and verified experimentally to stabilize the oscillation of circulation flow, to modify the flow patterns and to improve the performance. Focusing on various oscillators of plane-wall and step-wall designs, we systematically analyzed the pressure spectra, pressure loss, and flow structure, via particle-imaging velocimetry, flow visualization, and pressure sensors. The results reveal that the novel design promotes conditions to initiate the oscillator and makes the recirculation vortices oscillate more effectively and stably. The operating range of this step-wall oscillator is broadened and the ratio of signal to noise of the step oscillator is 17 times as great as that with plane walls at a greater flow rate, 65 L/min. Comparison of the wave form of the spectral analysis and the ratio of signal to noise over the entire experimental range further corroborates the superior features of the novel design. (c) 2006 Elsevier B.V. All rights reserved.