Influence of Internal mixing region on spray fluctuation in twin-fluid atomizer

Abstract

A twin-fluid atomizer with internal mixing chamber was developed and its performance was tested. The primary breakup took place in the internal mixing chamber, so the mass flow rate of air and water was measured and those ratios were presented vs. supplied pressure. In the present report, the oscillatory behavior of the spray produced by the developed twin-fluid atomizer was investigated to explore the stabilities of the spray. An optical observation was conducted to analyze the unsteady spray images with a high speed video camera. The images were inspected with FFT analysis and stream-wise oscillation spectrum was discussed for various supplied-air pressures and the length of the internal mixing chamber, L. When L is small, a strong resonance took place so that the spray is influenced by this phenomenon. However, the oscillation was suppressed then a stable atomization was provided by adjusting L. © Published under licence by IOP Publishing Ltd.