Discrete-phase simulation of single bubble rise behavior at elevated pressures in a bubble column

Numerical simulation is performed on the flow behavior of a bubble rising i n a liquid medium at high pressures. In the numerical scheme, a computation al fluid dynamics (CFD) method is used to account for the flow characterist ics of the continuous liquid phase and the gas phase inside the bubble. The Volume tracking based on the volume-of-fluid (VOF) method is used to descr ibe the free surface motion of gas bubble, and the deformational bubble sha pes. Simulations are performed simultaneously for both liquid and gas phase s by considering the volume-fraction-weighted averaged properties on the in terface. The behavior of a single gas bubble rising in Paratherm NF heat tr ansfer liquid at pressures of 0.1 and 19.4 MPa is simulated and compared wi th the experimental results obtained in this study. The comparison is satis factory. The results of the simulation indicate that as the pressure increa ses, the maximum stable bubble size decreases, which is in conformity with the experimental findings. (C) 2000 Elsevier Science Ltd. All rights reserv ed.