THRESHOLDS FOR TRANSIENT CAVITATION PRODUCED BY PULSED ULTRASOUND IN A CONTROLLED NUCLEI ENVIRONMENT
THRESHOLDS FOR TRANSIENT CAVITATION PRODUCED BY PULSED ULTRASOUND IN A CONTROLLED NUCLEI ENVIRONMENT
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DOI：
10.1121/1.400102
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发表时间：
1990-11-01
影响因子：
2.4
通讯作者：
APFEL, RE
中科院分区：
文献类型：
--
作者：
HOLLAND, CK;APFEL, RE
瞬态空化是一种离散现象，其起源依赖于稳定核或宿主流体内的气体袋的存在。用于评估瞬时空化的可能性的方便描述符是阈值压力，或启动气泡生长和随后的崩溃所需的最小声压。一个自动化的实验装置已被开发，以确定在流体中产生的空化的阈值，在0.76，0.99，和2.30 MHz的短音脉冲超声波。流体射流被用来通过声穿透换能器的聚焦区域对流潜在的空化核。所测试的潜在核包括1 μ m聚苯乙烯球、用人血清白蛋白稳定的1至10 μ m范围内的微泡和全血成分。空化检测的被动声学技术，是敏感的声音从空化气泡散射。在水中，在较高粘度的流体中，并在稀释的全血中的瞬态阈值的测量。这些空化阈值的实验测量阐明了超声波，宿主流体和核参数在确定这些阈值的重要性。这些结果被解释的上下文中的一个近似的分析理论的预测开始的空化。
Transient cavitation is a discrete phenomenon that relies on the existence of stabilized nuclei, or pockets of gas within a host fluid, for its genesis. A convenient descriptor for assessing the likelihood of transient cavitation is the threshold pressure, or the minimum acoustic pressure necessary to initiate bubble growth and subsequent collapse. An automated experimental apparatus has been developed to determine thresholds for cavitation produced in a fluid by short tone bursts of ultrasound at 0.76, 0.99, and 2.30 MHz. A fluid jet was used to convect potential cavitation nuclei through the focal region of the insonifying transducer. Potential nuclei tested include 1-.mu.m polystyrene spheres, microbubbles in the 1- to 10-.mu.m range that are stabilized with human serum albumin, and whole blood constituents. Cavitation was detected by a passive acoustical technique that is sensitive to sound scattered from cavitation bubbles. Measurements of the transient threshold in water, in a fluid of higher viscosity, and in diluted whole blood are presented. These experimental measurements of cavitation thresholds elucidate the importance of ultrasound, host fluid, and nuclei parameters in determining these thresholds. These results are interpreted in the context of an approximate analytical theory for the prediction of the onset of cavitation.