NUMERICAL MODELING OF CONDUCTION-DRIVEN BULK EVAPORATION AND CONDENSATION PROCESSES WITH CONSTANT VOLUME

This work is to develop a control volume finite-difference method to m odel the bulk evaporation and condensation processes involved in liqui d-vapour phase changes. An internal energy formulation, for these phas e change processes that occur under the constraint of constant volume, is proposed. All calculations are carried out on a fixed grid using t he cylindrical co-ordinate system. The well-established enthalpy formu lation and the proposed internal energy formulation are compared. Both formulations yield identical results with similar computational effic iencies, while the internal energy formulation has a more concise and compact form. Two iterative methods for the update of the vapour-phase fraction, the E-based and T-based methods, are investigated. Numerica l experiments reveal that for the evaporation problems, the E-based me thod is superior to the T-based method in terms of computational effic iency. The internal energy formulation and the E-based method are used to compute the bulk evaporation and condensation processes under diff erent conditions. The evolution of the phase change processes is inves tigated.