| In this research we consider the dynamics of a hydrocarbon bubble under varying pressure-temperature-composition fields. This is a two-phase two-region model where the momentum, mass, and energy balances are solved simultaneously over both liquid and gas regions. The physical phenomena occurring at the interface are considered including heat transfer, momentum continuity, and mass transfer. In the separate phase regions we consider mass convection, diffusion, heat conduction.;We use a spherical coordinate system and note that this geometry represents the linear geometry at large radii. The Lagrangian formulation is applied to the finite difference formulation that allows us to track the interface without interpolation or extrapolation. The mathematical model includes the constitutive equations of state for the fluids. A novel approach to the gas/liquid interface is developed and is termed the thermodynamic layer. In this thin layer equilibrium calculations are performed. It is this layer that is responsible for interface mass transfer.;The new model is used to study wave propagation in spherical and linear shells, the dynamics of bubble collapse including thermodynamic and inertial effects, and wave travel time in a buildup transient testing well. The main contribution of this research is the development of a modeling tool for studying the dynamics of bubble collapse with thermodynamic mass transfer, heat conduction, and inertial and momentum effects. We find the collapse of a fully reactive bubble is very different from the collapse of a cavitation bubble. During the collapse of a reactive bubble we have early time oscillations in response to sudden pressure changes linked with temperature oscillations. These early time phenomena occur before significant mass transfer and heat conduction occur. The timing of these effects and their magnitude depend on the composition of the fluids and the size of the bubble. The process is complicated and the design of the numerical modeling parameters must be done on a case by case basis.;The new model serves as a starting point for developing our understanding of multiphase flow phenomena. |
