Effects of ultrasonic cavitation on rate of heat propagation and longitudinal permeability of three U.S. hardwoods
1992
Chen, P.Y.S. | Simpson, W.T.
Several treatments have been attempted to make wood more uniformly permeable. One promising method is the application of ultrasonic cavitation on wood. Four sample blocks (2-in. cube) per species were directly cavitated without a coupling agent for 10 minutes at 120 W to study the heat propagation in green heartwood from sugar maple, black walnut, and white oak. Ten green heartwood sample blocks (2 by 2 by 1 in.) from 10 pairs of end-matched samples were also directly cavitated without a coupling agent for 10 minutes at 120 W for sugar maple and 5 minutes for black walnut and white oak. Specimen plugs were punched out from 10 pairs of samples to determine their longitudinal permeability before and after air-drying to evaluate the effect of ultrasonic cavitation on wood permeability. The rate of heat propagation in wood under ultrasonic cavitation appeared to depend on the permeability of the wood. Ultrasonic cavitation significantly increased the longitudinal permeability of the more permeable sugar maple, but did not alter the permeability of the less permeable black walnut and white oak.
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