Electrohydrodynamic atomization two-phase flow regime map for liquid hydrocarbon under pulsed electric fields with co-gas flow

2008 ◽  
Vol 66 (1-2) ◽  
pp. 94-98 ◽  
Author(s):  
J.S. Chang ◽  
C. Ayrault ◽  
D. Brocilo ◽  
D. Ewing ◽  
G.D. Harvel ◽  
...  
Keyword(s):  
Flow Regime ◽  
Electric Fields ◽  
Gas Flow ◽  
Pulsed Electric Fields ◽  
Liquid Hydrocarbon ◽  
Phase Flow ◽  
Two Phase ◽  
Regime Map ◽  
Flow Regime Map ◽  
Co Gas

Two-phase flow regime map predictions under microgravity

AIChE Journal ◽  
1988 ◽  
Vol 34 (1) ◽  
pp. 137-139 ◽  
Author(s):  
S. B. Reddy Karri ◽  
V. K. Mathur
Keyword(s):  
Flow Regime ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Regime Map ◽  
Flow Regime Map

Study of Interfacial Structures: Bubbly Flow in 1.27 cm Diameter Pipe

2002 ◽  
Author(s):  
S. Paranjape ◽  
S. Kim ◽  
M. Ishii ◽  
J. Uhle
Keyword(s):  
Flow Regime ◽  
Two Phase Flow ◽  
Bubbly Flow ◽  
Bubble Velocity ◽  
Phase Flow ◽  
Two Phase ◽  
Interfacial Structures ◽  
Radial Profiles ◽  
Regime Map ◽  
Flow Regime Map

The objective of the present research is to study the flow regime map, the detailed interfacial structures, and the bubble transport in an adiabatic air-water two-phase flow mixture, flowing upward through a vertical round pipe having 1.27 cm. inner diameter. The flow regime map is obtained by processing the characteristic signals acquired from an impedance void meter, using a self-organized neural network. The local two-phase flow parameters are measured by the state-of-the-art four-sensor conductivity probe at three axial locations in the pipe. The measured local parameters include void fraction (α), interfacial area concentration (ai), bubble frequency (fb), bubble velocity (Ub) and bubble Sauter mean diameter (Dsm). The radial profiles of these parameters and their development along the axial direction reveals the structure of the two phase mixture and the bubble interaction mechanisms.

scholarly journals Some problems of hydrodynamics of two-phase flow mixtures in minichannels

2014 ◽  
Vol 35 (2) ◽  
pp. 93-101
Author(s):  
Monika Wengel ◽  
Barbara Miłaszewicz ◽  
Roman Ulbrich
Keyword(s):  
Two Phase Flow ◽  
Early Stage ◽  
Phase Flow ◽  
Test Results ◽  
Two Phase ◽  
Key Issues ◽  
Gas Liquid Flow ◽  
Regime Map ◽  
Flow Regime Map

Abstract Gas-liquid two-phase flow in minichannels has been the subject of increased research interest in the past few years. Evaluation, however, of today’s state of the art regarding hydrodynamics of flow in minichannels shows significant differences between existing test results. In the literature there is no clear information regarding: defining the boundary between minichannels and conventional channels, labelling of flow patterns. The review of literature on the hydrodynamics of gas-liquid flow in minichannels shows that, despite the fact that many research works have been published, the problem of determining the effect of diameter of the minichannel on the hydrodynamics of the flow is still at an early stage. Therefore, the paperpresents the results of research concerning determination of flow regime map for the vertical upward flow in minichannels. The research is based on a comprehensive analysis of the literature data and on the research that has been carried out. Such approach to the mentioned above problems concerning key issues of the two-phase flow in minichannels allowed to determine ranges of occurrence of flow structures with a relatively high accuracy.

Visualization Study of Gas-Liquid Two-Phase Flow in a Hydrophobic Pipe

2007 ◽  
Author(s):  
Takayoshi Kikuchi ◽  
Tatsuya Hazuku ◽  
Yutaka Fukuhara ◽  
Tomoji Takamasa ◽  
Takashi Hibiki
Keyword(s):  
Flow Regime ◽  
Void Fraction ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Flow Characteristics ◽  
Phase Flow ◽  
Two Phase ◽  
Experimental Conditions ◽  
Churn Flow ◽  
Effect Of Surface

To evaluate the effect of pipe wall surface wettability on flow characteristics in a vertical upward gas-liquid two-phase flow, a visualization study was performed using an acrylic pipe and a hydrophobic pipe. Such basic flow characteristics as flow patterns, pressure drop and void fraction were investigated in these pipes. In the hydrophobic pipe, an inverted-churn flow regime was observed in a region where the churn flow regime was observed in the acrylic pipe, while a droplet flow regime was observed in the region where an annular flow regime was observed in the acrylic pipe. At a high gas flow rate, the average void fraction in the hydrophobic pipe was higher than in the acrylic pipe. The effect of surface wall wettability on frictional pressure loss was confirmed to be insignificant under the present experimental conditions.

Visualization and Predictive Modeling of Two-Phase Flow Regime Transition With Application Towards Water Management in the Gas-Flow Channels of PEM Fuel Cells

2005 ◽  
Author(s):  
Sang Young Son ◽  
Jeffrey S. Allen
Keyword(s):  
Fuel Cell ◽  
Flow Regime ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Phase Distribution ◽  
Pem Fuel Cells ◽  
Bond Number ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Channels

Understanding the behavior of gas and water vapor flow through the microchannel gas flow passages of a proton-exchange membrane (PEM) fuel cells is critical to reliable fuel cell operation. Recent research efforts have illustrated the importance of capillarity on the behavior of two-phase flow (gas-liquid) in low Bond number systems; that is, systems where capillary forces are important relative to gravitational forces. Such systems include capillary tubes and microchannels as well as the gas flow channels of a PEM fuel cell. The key characteristic scaling factors for two-phase flow in capillaries have been determined. The choice of length scales and velocity scales in dimensionless groups used to characterize two-phase flow is critical to correctly delineating phase distribution. Traditional scaling for these types of flows have considered the interaction between gas and liquid phases to be primarily inertial in nature. The role of liquid film stability where the phase interaction is a combination of viscous and capillary effects is shown to be a more appropriate scaling for low-Bond number, low-Suratman number two-phase flows. Microscopic visualization at high frame rates has been used to identify the flow regime under various gas-liquid mass ratios, channel geometries and surface energies. The observations collected via high speed microscopy and corresponding pressure measurements are reported for square and circular cross-sectional microchannels with contact angles of 20 degrees (hydrophilic) and 70 degrees (hydrophobic). The effect of geometry and contact angle on the phase distribution and the pressure drop are dramatic.

Experimental Study of Flow Regime Map in 5×5 Rod Bundle

2017 ◽  
Author(s):  
Hang Liu ◽  
Quanyao Ren ◽  
Liangming Pan ◽  
Takashi Hibiki ◽  
Wenxiong Zhou ◽  
...  
Keyword(s):  
Flow Regime ◽  
Gas Flow ◽  
Regime Transition ◽  
Rod Bundles ◽  
Flow Rates ◽  
Flow Regime Transition ◽  
Transition Criteria ◽  
Measured Flow ◽  
Regime Map ◽  
Flow Regime Map

In relation to development of the flow regime criteria for rod bundles, this paper provides an experimental flow regime map and compares the experimental map with the existing flow regime transition criteria for vertical rod bundles so far. An experiment of vertical adiabatic air-water flow was conducted under an atmosphere pressure conditions. The experiment facility was composed of 5×5 rod arranged on a square pitch in a square shell with 9.5 mm outside diameter and 12.6 mm pitch. A total of 242 data sets were acquired consisting of superficial gas flow rates, 0.02–8.69 m/s, and superficial liquid flow rates, 0.02–2.13 m/s. A new flow regime map was obtained and the flow regime transition model for rod bundles was validated by the measured flow regime map. A fairly good agreement with some discrepancies has been obtained between the existing flow regime transition criteria and measured flow regime maps for rod bundles.

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