Evolution of a Small Sphericity Distortion of a Vapor Bubble During Its Supercompression

摘要

The possibility of using two models to study the evolution and maximum increase in anlpli-tude ()Ismail distortions of sphericity ()la bubble during its strong compression in a liquid is investigated. The investigation is performed in the conditions of experiments On acoustic cavitation of deu-termed acetone. The first (fully hydrodynamic) model is based on the two-dimensional equations of gas dynamics. It is valid in every stage of the bubble compression. Hut its use takes up a lot of computational time. The second (simplified) model is derived by splitting the liquid and vapor motion into a spherical part and its small nonspherical perturbation. To describe the spherical component, a one-dimensional version oldie two-dimensional model is used in this The advantage of the simplified model over the full one is its much lower consumption of computational time. At the same time, the evolution of the nonspherical perturbation in this model is described by utilizing a number of assumptions, validity of which is justified only at the initial stage of the bubble compression. It is therefore logical to apply the simplified model at the initial low-speed stage of the bubble compression, while the full hydrodynamic one is applied at its final high-speed stage. It has been shown that such a combination allows one to significantly reduce the computational time. It has been found that the simplified model alone can be used to evaluate the maximum increase of the amplitude of smail sphericity distortions of a bubble during its compression.