Two-Zone PIV Analysis of Wavy and Wavy-Annular Two-Phase Flow

2008 ◽  
Author(s):  
DuWayne Schubring ◽  
Rory E. Foster ◽  
Timothy A. Shedd
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Reynolds Stresses ◽  
Wave Zone ◽  
Two Phase ◽  
Flow Rates ◽  
Micro Particle Image Velocimetry ◽  
Vector Maps ◽  
Piv Analysis ◽  
Image Pairs

Cross-sectional thin film micro-particle image velocimetry (cTFMPIV) analysis has been performed for air-water two-phase flow in a 19.05 mm horizontal duct. Images were captured by introducing a light sheet from a Nd:YAG laser into the flow, with the fluorescent emissions from three micron particles captured by a CCD camera behind a microscope objective and red filter. These images were grouped into pairs and digitally enhanced to isolate particle traces using commercial image processing software. Image pairs were collected for five air flow rates at each of four water flow rates and separated into base film and wave zones for PIV analysis. Using DaVis 7.1 (LaVision GmbH), vector maps were obtained for each pair. Less than 2% of the image pairs were removed due to clearly spurious vectors, while the appropriate zone for less than 8% of the image pairs could not be determined These pairs were grouped into a third batch. The vector maps were analyzed to calculate velocity profiles and turbulence (fluctuation) statistics in terms of wall coordinates. These statistics included intensities and Reynolds stresses. The base film shows laminar behavior beyond what would be expected from the universal velocity profile. The wave zone displays significantly different behavior and appears to reach an asymptote rapidly. Calculation of fluctuation intensities indicates a maximum within the wave zone along the gas-liquid interface, while the distribution of radial fluctuations in the base film and axial turbulence in all zones is approximately uniform. Calculation of the u′v′ shear Reynolds stress suggests that it has a negative value.

Experimental Determination of Two-Phase Flow Rates of Hydrocarbons Through Restrictions

2006 ◽  
Vol 84 (1) ◽  
pp. 40-53 ◽  
Author(s):  
S.M. Richardson ◽  
G. Saville ◽  
S.A. Fisher ◽  
A.J. Meredith ◽  
M.J. Dix
Keyword(s):  
Experimental Determination ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Rates

scholarly journals Measurement of Particle Flow Rates in Gas-Solid Two Phase Flow by a Piezoelectric Probe.

1997 ◽  
Vol 23 (5) ◽  
pp. 624-627
Author(s):  
Toshiro Tsuji ◽  
Toshiharu Shibata ◽  
Osamu Uemaki ◽  
Hironori Itoh
Keyword(s):  
Two Phase Flow ◽  
Particle Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Rates

Flow properties for the continuum viewpoint of a non-equilibrium gas-particle mixture

1968 ◽  
Vol 31 (2) ◽  
pp. 273-303 ◽  
Author(s):  
Ronald Panton
Keyword(s):  
Mass Transfer ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Particle Phase ◽  
Reynolds Stresses ◽  
Flow Properties ◽  
Two Phase ◽  
Local Flow ◽  
Particle Mixture ◽  
Non Equilibrium

Flow properties for the non-equilibrium two-phase flow of a gas-particle mixture are formulated from the theoretical standpoint. A quasi-one-dimensional flow containing an arbitrary volume of particles is considered, and mass transfer between the phases is allowed. It is shown that meaningful definitions of the flow properties of each phase can be constructed as area-averages of (time-averaged local flow-field properties). Special definitions of averages overcome the difficulties introduced by the fact that one phase does not occupy the entire region at all times. Conservation equations for the newly defined properties are given and criteria for their validity determined. The results give fresh interpretation to several aspects of two-phase flow: the particle-phase pressure is associated with the internal particle pressure, whereas Reynolds-stress terms are introduced by fluctuations in particle velocity. Reynolds stresses for both phases are important in laminar as well as turbulent flow and provide a significant particlephase viscous effect. The interphase momentum transfer because of condensation or vaporization is shown to be characterized by the particle-phase velocity irrespective of the direction of the mass transfer.

scholarly journals Correlative Mapping Method for Measuring Individual Phase Flow Rates of Air-Water Two-Phase Flow Based on Stochastic Features.

1997 ◽  
Vol 63 (612) ◽  
pp. 2707-2712
Author(s):  
Kiyoshi MINEMURA ◽  
Takeaki TAKEOKA ◽  
Shinji SHODA ◽  
Kazuyuki EGASHIRA ◽  
Yutaka OGAWA
Keyword(s):  
Two Phase Flow ◽  
Mapping Method ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Individual Phase

Flow Regime Evolution in Long, Serpentine Microchannels With a Porous Carbon Paper Wall

2008 ◽  
Author(s):  
Julie E. Steinbrenner ◽  
Eon Soo Lee ◽  
Fu-Min Wang ◽  
Chen Fang ◽  
Carlos H. Hidrovo ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Flow Regime ◽  
Liquid Flow ◽  
Liquid Water ◽  
Two Phase Flow ◽  
Pem Fuel Cells ◽  
Carbon Paper ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Rates

An important function of the gas delivery channels in Proton Exchange Membrane (PEM) fuel cells is the evacuation of liquid water created at the cathode. The resulting two-phase flow can become an obstacle to reactant transport and a source of parasitic losses. The present work examines the behavior of two-phase flow in 500 μm × 500 μm × 60 cm channels with distributed water injection through a porous carbon paper wall to gain understanding of the physics of flows relevant to fuel cell water management challenges. Flow regime maps based on local gas and liquid flow rates are constructed for experimental conditions corresponding to current densities between 0.5 and 1 A/cm2 and stoichiometric coefficients from 1 to 4. Flow structures are analyzed along the entire length of the channel. It is observed that slug flow is favored to plug flow at high air flow rates and low liquid flow rates. Stratified flow dominates at high liquid flow rates. Along the axial flow direction, the flow regime consistently transitions from intermittent to wavy to stable stratified flow. This progression is quantified using a parameter of flow progression which characterizes the degree of development of the two-phase flow toward the stable stratified condition. This parameter is discussed in relation to fuel cell operating conditions. It provides a metric for analyzing liquid water removal mechanisms in the cathode channels of PEM fuel cells.

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