Turbulent bubbly flow predictions with CFX4.2 computer code

The purpose of this paper is to investigate the ability of the CFX4.2 computer program to model adiabatic, turbulent, upward bubbly flow in a pipe. An effort was performed to estimate the numerical uncertainty of the calculation. Only then would a comparison of the calculations with experimental results clarify the shortcomings of the physical models. The comparison of the predictions with the experimental data indicates that the code was able to predict effects of liquid velocity flattening and turbulence intensity reduction caused by the presence of the bubbles. It was found that application of Sato's model of bubble induced turbulence led to a better agreement with the experiment. However, the calculation of the wall void fraction peak value was underpredicted. (author)