© 2004 Robert A. Freitas Jr. and Ralph C. Merkle. All Rights Reserved.

Robert A. Freitas Jr., Ralph C. Merkle, Kinematic Self-Replicating Machines, Landes Bioscience, Georgetown, TX, 2004.

B.4.4.2 Transient Cavitation

Ultrasound passing through liquids may produce transient bubbles which implode, producing temperature increases of ~10³ K and pressure spikes of ~10³ atm localized in regions of a few microns in radius. In water, normal or transient cavitation requires an irradiation intensity of ~10⁵ W/m² (~5.4 atm) at 30 KHz or ~10⁶ W/m² (~17 atm) at 1 MHz [3258]. Relevant thermodynamic constants for liquid n-octane lie within an order of magnitude of the same values for water, so 10 MHz operation in liquid n-octane at I_acoustic ~ 6100 W/m² for DP ~ 1 atm (Section B.3) is not expected to produce transient cavitation. However, this expectation should be verified experimentally.

Last updated on 13 August 2005