Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
LIQUID VELOCITY PROFILES AND WALL SHEAR STRESS ESTIMATION IN WATER-AIR HORIZONTAL INTERMITTENT FLOWS
Submission Author:
Leonardo Soares Fernandes , RJ , Brazil
Co-Authors:
Leonardo Soares Fernandes, Rodrigo dos Santos Navarro de Mesquita, Rafaela Medeiros, Luis Fernando Alzuguir Azevedo
Presenter: Leonardo Soares Fernandes
doi://10.26678/ABCM.COBEM2019.COB2019-1194
Abstract
The main goal of this work is to evaluate the liquid velocity profiles and estimate the wall shear stress (WSS), in the liquid plug, during intermittent gas-liquid flows in a horizontal pipe. An acrylic pipe with total length of 18m and inner diameter of 40mm was used as test section, while air and water with superficial velocities of JG = 0.5 m/s and JL = 0.3, 0.4 and 0.5m/s were used as working fluid. Velocity fields measurements were performed using a high-frequency stereoscopic particle image velocimetry (SPIV) system along with the laser induced fluorescence (LIF) technique. A set of three equally-spaced photogates were used to measure two-phase flow statistics and to trigger data acquisition, what allowed the calculation of ensemble-averaged velocity fields at equally time-spaced cross-section planes, using the gas-bubble nose tip as reference. WSS was estimated based on the Clauser method, using the measured averaged velocity profiles. The small time step between each measurement plane along the slug unit cell allowed the determination of the length to the gas-bubble nose into which the velocity profile is no longer influenced by the faster moving gas bubble. The data presented are of great importance to the improvement and validation of numerical models, specially the one-dimensional ones.
Keywords
Intermittent flow, Wall Shear Stress, Gas-Liquid Flow, Velocity field
