THE DRIFT-FLUX MODEL APPLIED TO BUBBLE-COLUMNS AND LOW VELOCITY FLOWS

Although the drift-flux model is well-established for use in high velocity bubble flows, many researchers have found the need to alter the model to deal with low velocities or large diameter pipes. Based on some preliminary bubble distribution data from a 15.2 cm dia bubble column and on data in the literature, a program has been written to establish values for the drift-flux profile constant C0 when it is influenced by buoyancy effects. It is concluded that the drift-flux model must be used with caution since C0 can vary from <1 to values >10 under extreme circumstances. However, C0 is shown to assume the accepted values in higher velocity flows where buoyancy can be neglected. In addition, a technique is presented for predicting circulation in a column without prior knowledge of the void (bubble) distribution. © 1990.