INTERFACIAL SHEAR MEASUREMENT FOR 2-PHASE GAS-LIQUID FLOW BY MEANS OF PRESTON TUBES

Impact tubes installed on the walls of a wind tunnel were used to measure the shear stress distribution along the top and side walls for concurrent air-water stratified flow. By means of a momentum balance on the gas phase the interfacial shear exerted on the liquid film is computed from the shear stress distribution, pressure drop, and average film thickness. The method is compared with other techniques, and the effects of neglecting the side wall shear stress in the calculation of the interfacial shear are determined. Interfacial shear stresses, local wall shear stresses, pressure drop data, and film thickness characteristics are presented and, where possible, compared with literature results. Significant disagreement among values of smooth wall shear stresses and interfacial shear stresses reported in the literature has been found. © 1969, American Chemical Society. All rights reserved.