Interfacial Friction in Gas-Liquid Annular Flow: Analogies to Full and Transition211 Roughness

摘要

New film thickness and pressure gradient data were obtained in a 5.08 by 101.6 mm211u001educt for nitrogen and water in annular flow. Pressures of 3.4 and 17 atm and 211u001etemperatures of 38 and 93 C were used to vary the gas density and liquid 211u001eviscosity. These data are used to compute interfacial shear stresses and 211u001einterfacial friction factors for comparison with several accepted literature 211u001ecorrelations. These comparisons are reasonable for small values of the relative 211u001efilm thickness. However, the new data cover conditions not approached by the data 211u001eused to construct those correlations. By combining the current data with the 211u001eresults of two other comprehensive modern experimental studies, a new correlation 211u001efor the interfacial friction factor has been developed. This correlation adds 211u001eelements of transition roughness to Wallis' fully-rough analogy to better predict 211u001einterfacial friction factors over a wide range of gas Reynolds numbers and liquid 211u001efilm thicknesses.