Aerosol manipulation by acoustic tunable phase-control at resonant frequency

Abstract

The aerosols regularly manipulated by modular platform of acoustic tunable phase-control at resonant frequency 2.6427kHz are demonstrated in this paper. In order to make full of the superimposition of multiple waves in nonuniform two dimension acoustic standing wave field, the modular platform is composed of the square cavity and the two pairs of symmetric acoustic sources with Helmholtz resonators. The modular platform allows that the effective volume of cavity is 32.8 (length)×32.8 (width)×5 (height)cm3 and also the tunable acoustic phase-control is realized by proposed two different phase modes named π-mode phase and 0-mode phase. The ranges of the aerosol size distribution and the aerosol concentration are 0.08μm–1μm and 51.6–93.3% (Opacity), respectively. The experimental temperature remains at 298K. Results indicate that the platform causes perfect nonuniform two-dimension acoustic standing wave field. Under the condition of π-mode phase, the manipulation is better than that under 0-mode phase; the characteristic length of X-pattern for displaying the manipulation is half-wavelength larger than quarter-wavelength acquired in one-dimension acoustic standing wave field. The major areas to remove aerosols are 39cm2 under π-mode phase and 9.7cm2 under 0-mode phase. The phase is an important parameter for impacting the manipulation of aerosols. For explaining the difference of manipulation under the two phase conditions, the relative structural factors of acoustic field are found and considered as the intermediate variables from acoustic tunable phase to aerosol manipulation. Especially, the large neck for the shape of sound pressure nodes might cause weak interaction between aerosols and acoustic field and further result in the unexhaustive manipulation.