On the use of the stratified momentum balance for the deduction of shear stress in horizontal gas–liquid pipe flow

• Published in: International journal of multiphase flow Vol. 24; no. 8; pp. 1407 - 1423
• Main Authors: Newton, C.H., Behnia, M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.1998; Elsevier
• Subjects: Exact sciences and technology; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Friction factor; Fundamental areas of phenomenology (including applications); Horizontal; Instrumentation for fluid dynamics; Momentum balance; Multiphase and particle-laden flows; Nonhomogeneous flows; Physics; Stratified; Two-phase; Uncertainty analysis; Stratified; Friction factor; Horizontal; Two-phase; Uncertainty analysis; Momentum balance; Horizontal pipe; Gas liquid interface; Two-phase flow; Pressure drop; Correlations; Bias; Shear stress; Momentum; Experimental study; Stratified flow
• ISSN: 0301-9322; 1879-3533
• DOI: 10.1016/S0301-9322(98)00023-8

The use of the stratified flow momentum balance for the deduction of interfacial and liquid wall shear stresses from experimental measurements is examined. A systematic error analysis is applied to the governing equations using the principle of maximum uncertainty. A series of air–water experiments were conducted in 50 and 80 mm diameter pipes, in which gas pressure drop, liquid height and gas wall shear stress were measured. A framework for the correlation of the deduced shear stresses is proposed from the experimental measurements. The uncertainty analysis is used to show that the definition of mean liquid height does not significantly influence the overall results. The development of empirical equations based on such methods may lead to total uncertainties of up to 40%, irrespective of accuracy of the experimental data or the appropriateness of the correlating technique. Comparisons with state-of-the-art correlations for the liquid wall and interfacial friction factor data showed even larger discrepancies between measurement and prediction.