Oscillation regimes of gas/vapor bubbles

In this work we investigate the effect of heat and mass transfer on the dynamics of gas-vapor bubbles. We present phase diagrams for the bubble oscillation regimes, which are built by comparison of various models with different level of simplification for an air-water system. These diagrams show the range of validity of the simplifying assumptions on the Peclet-numberivapor-content plane, providing an insight on the physical process which regulates the bubble response with respect to external pressure perturbations. The analysis is presented for both the linear and weakly non-linear regime. In the former case we use linearized solutions of the full system; in the latter, numerical simulations validated against the analytical solutions in the linear limit. We show that even at very low frequencies, there exist regimes where transient diffusion effects arise and restrict the applicability of the commonly-adopted assumption of full-equilibrium conditions inside the bubble. Non-linearity is found to restrict even further the range of applicability of this hypothesis, due to the variation of the vapor content beyond a critical value. (C) 2017 Elsevier Ltd. All rights reserved.