Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
Evaluation of Wall Shear Stress Distribution in Upward Slug Flow
Submission Author:
jonathan nobrega , SP
Co-Authors:
Eugênio Spanó Rosa
Presenter: jonathan nobrega
doi://10.26678/ABCM.ENCIT2016.CIT2016-0032
Abstract
The main purpose of this work is to investigate the local wall shear stress distribution of the gas-liquid upward slug flow in a vertical pipe. It has been shown in the literature that wall shear stress, when associated with flow hydrodynamics, is responsible for enhancing the corrosion ratio in pipelines. The lack of knowledge of the non-uniform behavior of wall shear stress in such flow pattern and its implication on corrosion phenomenon is the key factor for developing this work. Studies were carried out in a slug unit (liquid plug + Taylor bubble) for tubes with 50, 75 and 100 mm ID and superficial mixture velocity varying from 1, 2 and 3 m/s. In order to investigate the wall shear stress distribution on Taylor bubble region, the film model by Taitel and Barnea (1990), which is the most complete model developed so far, is used. In addition, the investigation of this variable profile on the liquid plug is carried out using a CFD program, PHOENICS (2011). A two-dimensional coordinate system assuming axial symmetry about their centerline is considered. It is used the standard k-e model modified by Chen and Kim (1987) to simulate the turbulence. The results show that the wall shear stress changes its signal twice over the whole slug unit. One transition takes place near the Taylor bubble nose and another one, near of its rear. It can be seen the non-uniformity of wall shear stress both in Taylor bubble and liquid plug.
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