Visualization of acoustic particle interaction and agglomeration: Theory evaluation
- Center for Acoustics and Vibration, The Pennsylvania State University, 157 Hammond Building, University Park, Pennsylvania 16802 (United States)
In this paper experimentally observed trajectories of particles undergoing acoustically induced interaction and agglomeration processes are compared to and validated with numerically generated trajectories based on existing agglomeration theories. Models for orthokinetic, scattering, mutual radiation pressure, and hydrodynamic particle interaction are considered in the analysis. The characteristic features of the classical orthokinetic agglomeration hypothesis, such as collision processes and agglomerations due to the relative entrainment motion, are not observed in the digital images. The measured entrainment rates of the particles are found to be consistently lower than the theoretically predicted values. Some of the experiments reveal certain characteristics which may possibly be related to mutual scattering interaction. The study`s most significant discovery is the so-called tuning fork agglomeration [T. L. Hoffmann and G. H. Koopmann, J. Acoust. Soc. Am. {bold 99}, 2130{endash}2141 (1996)]. It is shown that this phenomenon contradicts the theories for mutual scattering interaction and mutual radiation pressure interaction, but agrees with the acoustic wake effect model in its intrinsic feature of attraction between particles aligned along the acoustic axis. A model by Dianov {ital et al.} [Sov. Phys. Acoust. {bold 13} (3), 314{endash}319 (1968)] is used to describe this effect based on asymmetric flow fields around particles under Oseen flow conditions. It is concluded that this model is consistent with the general characteristics of the tuning fork agglomerations, but lacks certain refinements with respect to accurate quantification of the effect. {copyright} {ital 1997 Acoustical Society of America.}
- DOE Contract Number:
- AC21-89MC26288
- OSTI ID:
- 548766
- Journal Information:
- Journal of the Acoustical Society of America, Vol. 101, Issue 6; Other Information: PBD: Jun 1997
- Country of Publication:
- United States
- Language:
- English
Similar Records
An improved theoretical model of acoustic agglomeration
Simulation of acoustic agglomeration processes of poly-disperse solid particles