VI-1

A. Pearson and T. Hammond

Schlumberger

Abstract

ID models for vertical gas liquid flow relate certain mean (averaged) quantities, i. e. phase velocities, pressures and fractions, using momentum equations characterized by assumed constitutive models for the interphase force; solutions are tested against experiments in pipes of varying cross-section. It can be shown theoretically that steady solutions of most models that adequately predict Venturi flowmeter pressure drops are linearly unstable, a feature not incompatible with observation. The hyperbolic nature of various models and the form of corresponding eigen solutions is examined. The effect of axial velocity fluctuatuions and cross-sectional non-uniformity are discussed.

Problems with stratified flow models assuming the long-wave approximation for liquid-liquid flow in nearly horizontal pipes will be presented. Issues of sub-and super-criticality leading to possible non-existence of steady solutions will be discussed.