Bapat Pratap S, Pandit Aniruddha B
Chemical Engineering Department, University Institute of Chemical Technology, Matunga, Mumbai 400019, India.
Ultrason Sonochem. 2008 Jan;15(1):65-77. doi: 10.1016/j.ultsonch.2007.01.005. Epub 2007 Feb 3.
Qualitative explanation for a homogeneous nucleation of acoustic cavitation bubbles in the incompressible liquid water with simple phenomenological approach has been provided via the concept of the desorbtion of the dissolved gas and the vaporization of local liquid molecules. The liquid medium has been viewed as an ensemble of lattice structures. Validity of the lattice structure approach against the Brownian motion of molecules in the liquid state has been discussed. Criterion based on probability for nucleus formation has been defined for the vaporization of local liquid molecules. Energy need for the enthalpy of vaporization has been considered as an energy criterion for the formation of a vaporous nucleus. Sound energy, thermal energy of the liquid bulk (Joule-Thomson effect) and free energy of activation, which is associated with water molecules in the liquid state (Brownian motion) as per the modified Eyring's kinetic theory of liquid are considered as possible sources for the enthalpy of vaporization of water molecules forming a single unit lattice. The classical nucleation theory has then been considered for expressing further growth of the vaporous nucleus against the surface energy barrier. Effect of liquid property (temperature), and effect of an acoustic parameter (frequency) on an acoustic cavitation threshold pressure have been discussed. Kinetics of nucleation has been considered.
通过溶解气体解吸和局部液体分子汽化的概念，采用简单的唯象方法对不可压缩液态水中声空化气泡的均匀成核进行了定性解释。液体介质被视为晶格结构的集合。讨论了晶格结构方法相对于液态分子布朗运动的有效性。为局部液体分子的汽化定义了基于成核概率的判据。汽化焓所需的能量被视为气态核形成的能量判据。根据修正的艾林液体动力学理论，声能、液体整体的热能（焦耳-汤姆逊效应）以及与液态水分子（布朗运动）相关的活化自由能被视为形成单个单位晶格的水分子汽化焓的可能来源。然后考虑了经典成核理论，以描述气态核在表面能垒作用下的进一步生长。讨论了液体性质（温度）和声参数（频率）对声空化阈值压力的影响。考虑了成核动力学。
