ASA 124th Meeting New Orleans 1992 October

5aPAb2. Trajectories and interaction of two particulates in an acoustic field.

Thomas L. Hoffmann

Ctr. for Acoust. and Vib., Penn State Univ., 157 Hammond Bldg., University Park, PA 16802

A numerical and experimental study is presented to visualize trajectories of a pair of particulates entrained in an acoustic field. A numerical scheme is developed for determinating the relative path of the particles under the influence of orthokinetic, scattering, and hydrodynamic forces. The importance of the different interaction mechanisms is evaluated for varying frequencies and sound-pressure levels. A bench-top experimental setup is used to visualize actual particle trajectories in a sound field with a high-speed video system. These trajectories are then mapped to determine the actual relative particle path of one particle against the other. The results of a comparison between the numerical simulations and the experimental visualizations are used to assess the validity of the existing theoretical models in respect to orthokinetic, scattering, and hydrodynamic interaction mechanisms.