Investigation on average void fraction for air/nonNewtonian powerlaw fluids twophase flow in downward inclined pipes
Abstract
The present work has been carried out to investigate on the average void fraction of gas/nonNewtonian fluids flow in downward inclined pipes. The influences of pipe inclination angle on the average void fraction were studied experimentally. A simple correlation, which incorporated the method of Vlachos et al. for gas/Newtonain fluid horizontal flow, the correction factor of Farooqi and Richardson and the pipe inclination angle, was proposed to predict the average void fraction of gas/nonNewtonian powerlaw stratified flow in downward inclined pipes. The correlation was based on 470 data points covering a wide range of flow rates for different systems at diverse angles. A good agreement was obtained between theory and data and the fitting results could describe the majority of the experimental data within {+}20%. (author)
 Authors:
 LHO, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China)
 Publication Date:
 OSTI Identifier:
 21350405
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Experimental Thermal and Fluid Science; Journal Volume: 34; Journal Issue: 8; Other Information: Elsevier Ltd. All rights reserved
 Country of Publication:
 United States
 Language:
 English
 Subject:
 42 ENGINEERING; AIR; PIPES; TWOPHASE FLOW; VOID FRACTION; LIQUID FLOW; CORRELATIONS; ORIENTATION; FLOW RATE; CORRECTIONS; COVERINGS; NonNewtonian fluids
Citation Formats
Xu, Jingyu. Investigation on average void fraction for air/nonNewtonian powerlaw fluids twophase flow in downward inclined pipes. United States: N. p., 2010.
Web. doi:10.1016/J.EXPTHERMFLUSCI.2010.07.012.
Xu, Jingyu. Investigation on average void fraction for air/nonNewtonian powerlaw fluids twophase flow in downward inclined pipes. United States. doi:10.1016/J.EXPTHERMFLUSCI.2010.07.012.
Xu, Jingyu. 2010.
"Investigation on average void fraction for air/nonNewtonian powerlaw fluids twophase flow in downward inclined pipes". United States.
doi:10.1016/J.EXPTHERMFLUSCI.2010.07.012.
@article{osti_21350405,
title = {Investigation on average void fraction for air/nonNewtonian powerlaw fluids twophase flow in downward inclined pipes},
author = {Xu, Jingyu},
abstractNote = {The present work has been carried out to investigate on the average void fraction of gas/nonNewtonian fluids flow in downward inclined pipes. The influences of pipe inclination angle on the average void fraction were studied experimentally. A simple correlation, which incorporated the method of Vlachos et al. for gas/Newtonain fluid horizontal flow, the correction factor of Farooqi and Richardson and the pipe inclination angle, was proposed to predict the average void fraction of gas/nonNewtonian powerlaw stratified flow in downward inclined pipes. The correlation was based on 470 data points covering a wide range of flow rates for different systems at diverse angles. A good agreement was obtained between theory and data and the fitting results could describe the majority of the experimental data within {+}20%. (author)},
doi = {10.1016/J.EXPTHERMFLUSCI.2010.07.012},
journal = {Experimental Thermal and Fluid Science},
number = 8,
volume = 34,
place = {United States},
year = 2010,
month =
}

Much work has been done in the area of twophase upflow, while the flow of gas and liquid in the downward direction has not received much attention. This paper presents a model for estimating void fraction in downward flow for vertical and inclined systems for the two dominant flow regimes, bubbly flow and slug flow. The author uses the driftflux approach to determine slip between the phases and the transition between the flow regimes. The flowing mixture densities calculated from the model are useful for pressure gradient estimation. Extensive data are used to validate the model. The data show thatmore »

Flow pattern, pressure drop and void fraction of twophase gasliquid flow in an inclined narrow annular channel
Twophase flow pattern, pressure drop and void fraction in horizontal and inclined upward airwater twophase flow in a minigap annular channel are experimentally studied. A concentric annular test section at the length of 880mm with an outer diameter of 12.5mm and inner diameter of 8mm is used in the experiments. The flow phenomena, which are plug flow, slug flow, annular flow, annular/slug flow, bubbly/plug flow, bubbly/slugplug flow, churn flow, dispersed bubbly flow and slug/bubbly flow, are observed and recorded by highspeed camera. A slug flow pattern is found only in the horizontal channel while slug/bubbly flow patterns are observed onlymore » 
Countercurrent twophase flow regimes and void fraction in vertical and inclined channels
Countercurrent flow limitation (CCFL), or flooding, is one of the most significant aspects of countercurrent twophase flow. The CCFL imposes a limitation on the operational parameters for systems involving countercurrent flow and can have important adverse consequences during the course of various nuclear reactor accidents. Much attention has, therefore, been paid to the CCFL phenomenon. Gravitydriven countercurrent twophase flow in horizontal and inclined channels, where the flows of both liquid and gas phases are due to the effect of gravity, has recently been studied because of its potential occurrence in the safety cooling systems of advanced reactors. Hydrodynamic characteristics ofmore » 
An experimental study on downward slug flow in inclined pipes
The downward simultaneous flow of gas and liquid is often encountered in hilly terrain pipelines and injection wells. Most of the methods for predicting pressure drop in gas/liquid, twophase flow in pipes have been developed for either upward vertical or upward inclined pipes. This study experimentally investigated downward cocurrent slug flow in inclined pipes. A new test facility was designed and built to acquire data for the entire range of pipe inclination angles. A series of slug flow experiments was conducted in a 2in. diameter, 65ft long clear PVC pipe installed on an inclinable structure. Liquid holdup and pressure dropmore » 
Well test analysis for twophase flow of nonNewtonian powerlaw and Newtonian fluids
Analysis of injectivity and falloff test data is considered during twophase flow of nonNewtonian and Newtonian fluids. The nonNewtonian fluids considered are powerlaw fluids. Two sets of relative permeability data representing preferentially water wet and oil wet systems are considered. The conditions under which saturation gradients develop are thoroughly investigated. The effects of finite radius skin region and rock compressibility on pressure response are also investigated. During twophase flow of powerlaw and Newtonian fluids, saturation gradients do not develop under most practical conditions. Injectivity and falloff data can be analyzed using available techniques with appropriate definitions of dimensionless variables formore »