ID 225

Towards a multicomponent real-fluid fully compressible two-phase flow model

 

Abstract:

A fully compressible two-phase flow with four-equation model coupled with a real-fluid multi-component phase equilibrium solver is proposed. It is composed of two mass conservation equations, one momentum equation and one energy equation under the assumptions of mechanical and thermal equilibri-um. The phase equilibrium solver is developed based on the Peng-Robinson equation of state. To be more specific, this solver not only includes the entire processes of vapor-liquid equilibrium covering phase stability analysis which is based on tangent plane distance (TPD) method [24] and isothermal-isobaric flash (TPn) [25], but also involves an isoenergetic-isochoric (UVn) flash [27] for the computation of equi-librium temperature, pressure and phase compositions. This model named as 4EQ-PR has been imple-mented into an in-house IFP-C3D software [8]. Comparisons between the predictions of the 4EQ-PR mod-el with available numerical results in literature have been carried out. The compared results demonstrated that the 4EQ-PR model can well reproduce the multicomponent real-fluid behaviors in subcritical and transcritical conditions with phase change, and strong shock wave in supercritical conditions. Finally, the proposed 4EQ-PR model has been applied to typical 3D injection modeling including the classical super-critical and transcritical injection regimes. It has been demonstrated that the simulation results can be cor-related with relevant theories and experiments very well. In particular, analysis of the phase state (TPD) contour in different thermodynamic regimes has led to better understanding for the phase change process around the liquid core in transcritical conditions.