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Shock Waves in Liquids with Two-phase Bubbles | |

An investigation of wave processes in liquids with "two-phase" bubbles containing evaporating drops with interphase heat and mass transfer is presented. A single-velocity two-pressure model is used which takes into account both the liquid radial inertia due to medium volume changes, and the temperature distribution inside and around the bubbles. An analysis of the microsopic fields of physical parameters is aimed at closing the system of equations for averaged characteristics. The original system of differential equations of the model is modified to a form suitable for numerical integration. The evolution of non-steady shock waves in liquids with bubbles containing evaporating drops is studied by numerical methods. The effect of the initial conditions, shock strength, volume fraction, dispersity of the vapor phase, initial static pressure and of the thermophysical properties of the phases on shock-wave structure and evolution is studied. The results obtained have proved that the interphase heat and mass transfer greatly influences the wave structure. It is shown that the wave propagates in a mixture with increasing pressure rather than in one with uniform parameters. This is because, as distinct from mixtures with gas or vapor bubbles, the wave is preceded by a process of liquid evaporation into the vapor layer and hence a pressure increase in the vapor layer and in the mixture. The possible enhancement of disturbances in the region of their initiation is shown. The phenomenon of the nonlinear anomalous enhancement of waves reflected from a wall is established. |