Evolution of statistical parameters of gas-liquid slug flow along verticalpipes

The evolution of hydrodynamic and statistical parameters along the pipe was studied experimentally in gas-liquid slug flow for various flow conditions and two pipe diameters. The measuring modules comprise a set of three adja cent optical fiber probes and could be easily transferred to various positi ons along the pipes. The probes detect the passage of the gas-liquid interf ace. This technique enables one to measure the instantaneous velocities of nose and tail of elongated (Taylor) bubbles simultaneously with the slug le ngth ahead of each bubble. The liquid slug and Taylor bubble length distrib utions along the pipe, together with the dependence of the Taylor bubble ve locity on the liquid slug length ahead of it, are presented at various loca tions along the pipe. Empirical correlations relating the Taylor bubble vel ocity with the bubble separation distance are suggested. These correlations are used as an input to a model for slug length distribution. The model re sults are compared with the experiments. (C) 2001 Elsevier Science Ltd. All rights reserved.