Di!using acoustic wave spectroscopy of #uidized suspensions
نویسندگان
چکیده
The velocity #uctuations and local strain rate in a #uidized suspension of particles are investigated using the new ultrasonic technique of di!using acoustic wave spectroscopy. DAWS probes the relative motion of the particles at very short length scales down to the inter-particle separation, and allows the spatial correlations of the velocity #uctuations to be probed by varying the transport mean free path of the di!using ultrasonic waves. Our results demonstrate the power of this ultrasonic technique to probe the dynamics of sedimenting particles at larger length scales and Reynolds numbers than can be achieved by light scattering methods. ( 2000 Elsevier Science B.V. All rights reserved.
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