Effects of Channel Length on Gas-Liquid Two-Phase Flow Phenomena in a Microchannel

2011 ◽  
Author(s):  
Hideo Ide ◽  
Ryuji Kimura ◽  
Masahiro Kawaji
Keyword(s):  
Void Fraction ◽  
Flow Rate ◽  
Liquid Flow ◽  
Mass Velocity ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Optical Measurement ◽  
Phase Flow ◽  
Two Phase ◽  
The Mean

An optical measurement system was used to investigate the effect of microchannel length on the characteristics of adiabatic gas-liquid two-phase flow. Experiments were conducted with a 1,676 mm long, circular microchannel with an inner diameter of 100 μm. Two-phase flow patterns, void fraction and velocities of gas plug/slug and liquid slugs were measured at different locations between the gas-liquid mixer and channel exit. The experimental values of the mean void fraction and the mean velocity of liquid slug agreed well with the homogeneous flow model predictions when the liquid flow rate was constant and the mass velocity of the gas was low. The flow pattern transition from slug flow to ring film flow was observed when the mass velocity of the gas was increased while the liquid flow rate was kept constant.

Wet Gas Flow Metering Based on Differential Pressure and BSS Techniques

2011 ◽  
Vol 383-390 ◽  
pp. 4922-4927
Author(s):  
Peng Xia Xu ◽  
Yan Feng Geng
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Differential Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Metering ◽  
Wet Gas

Wet gas flow is a typical two-phase flow with low liquid fractions. As differential pressure signal contains rich information of flow parameters in two-phase flow metering, a new method is proposed for wet gas flow metering based on differential pressure (DP) and blind source separation (BSS) techniques. DP signals are from a couple of slotted orifices and the BSS method is based on time-frequency analysis. A good relationship between the liquid flow rate and the characteristic quantity of the separated signal is established, and a differential pressure correlation for slotted orifice is applied to calculate the gas flow rate. The calculation results are good with 90% relative errors less than ±10%. The results also show that BSS is an effective method to extract liquid flow rate from DP signals of wet gas flow, and to analysis different interactions among the total DP readings.

Modeling Oscillatory Behavior of Electrical Submersible Pump Wells Under Two-Phase Flow Conditions

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Rinaldo Antonio de Melo Vieira ◽  
Mauricio Gargaglione Prado
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Oscillatory Behavior ◽  
Phase Flow ◽  
Submersible Pump ◽  
Flow Conditions ◽  
Two Phase ◽  
Electrical Submersible Pump

The effect of free gas on electrical submersible pump (ESP) performance is well known. At a constant rotational speed and constant liquid flow rate, a small amount of gas causes a mild head reduction when compared to the single phase liquid head. However, at higher gas rates, a drastic reduction in the head is observed. This critical condition, known as the surging point, is a combination of liquid and gas flow rates that cause a maximum in the head performance curve. The first derivative of the head with respect to the liquid flow rate changes sign as the liquid flow rate crosses the surging point. In several works on ESP two-phase flow performance, production conditions to the left of the surging region are described or reported as unstable operational conditions. This paper reviews basic concepts on stability of dynamical systems and shows through simulation that ESP oscillatory behavior may result from two-phase flow conditions. A specific drift flux computation code was developed to simulate the dynamic behavior of ESP wells producing without packers.

Effect of Channel Length on the Gas-Liquid Two-Phase Flow Phenomena in a Microchannel

2009 ◽  
Author(s):  
Ryuji Kimura ◽  
Hideo Ide ◽  
Hiroshi Hashiguchi ◽  
Masahiro Kawaji
Keyword(s):  
Void Fraction ◽  
Test Section ◽  
Two Phase Flow ◽  
Optical Measurement ◽  
Liquid Velocity ◽  
Flow Characteristics ◽  
Phase Flow ◽  
Two Phase ◽  
Liquid Plug ◽  
The Mean

An optical measurement system was used to investigate the effect of microchannel length on adiabatic gas-liquid two-phase flow characteristics. Experiments were conducted with 146 mm and 1,571 mm long, circular microchannels of 100 micron diameter. Two-phase flow patterns, void fraction, gas and liquid plug lengths and their velocities were measured for two inlet configurations and gas-liquid mixing, i.e., (a) reducer and (b) T-junction. The test section length was found to have a significant effect on the two-phase flow characteristics measured at the same axial location in the microchannel test section typified by the void fraction data. The mean void fraction data obtained in the shorter (146 mm) microchannel with the reducer inlet agreed well with the equation by Kawahara and Kawaji which was previously proposed. On the other hand, the mean void fraction obtained at 36 mm from the inlet in the longer (1,571 mm) microchannel corresponded well with the homogeneous flow model and Armand’s equation for both reducer and T-junction inlet configurations. In the present experimental ranges of superficial gas velocity, jG = 0.03 ∼ 14 m/s, and superficial liquid velocity, jL = 0.04∼0.7 m/s, the gas and liquid plugs obtained in the longer microchannel had relatively shorter lengths and higher velocities than those in the shorter channel. Thus, both the microchannel length and inlet geometry were found to affect the two-phase flow characteristics in a microchannel.

Modeling Oscillatory Behavior of ESP Wells Under Two-Phase Flow Conditions

2012 ◽  
Author(s):  
Rinaldo Antonio de Melo Vieira ◽  
Mauricio Gargaglione Prado
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Oscillatory Behavior ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Operational Conditions

The effect of free gas on the Electrical Submersible Pump (ESP) performance is well known. At a constant rotational speed and constant liquid flowrate, small amount of gas causes a mild head reduction when compared to the single phase liquid head. However, at higher gas rates, a drastic reduction in the head is observed. This critical condition, known as surging point, is a combination of liquid and gas flow rates that cause a maximum in the head performance curve. The first derivative of the head with respect to the liquid flow rate change sign as the liquid flow rate crosses the surging point. In several works on ESP two-phase flow performance, production conditions to the left of the surging region are described or reported as unstable operational conditions. This paper reviews basic concepts on stability of dynamical systems and shows through simulation that ESP oscillatory behavior may result from two-phase flow conditions. A specific drift flux computation code was developed to simulate the dynamic behavior of ESP wells producing without packer.

scholarly journals Experimental Study on Hydraulic Characteristics of Pneumatic Lifting Pump

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 388
Author(s):  
Juanli Zuo ◽  
Fengchao Li ◽  
Ning Zhang ◽  
Denghui He ◽  
Wen Wang ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Flow Rate ◽  
Liquid Flow ◽  
High Speed ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Bubble Formation ◽  
Phase Flow ◽  
Hydraulic Characteristics ◽  
Two Phase

A pneumatic lifting pump is used in sewage treatment, offshore oil production, and other fields because of its simple structure and strong practicability. In order to study its internal hydraulic characteristics and gas-liquid two-phase flow, this paper carries out experimental research on the influence of different air intake modes and riser diameters on the performance of a pneumatic lifting pump. The air-water two-phase flow pattern in the riser and motion characteristics of bubble formation at the nozzle are obtained by a high-speed camera. Through theoretical analysis, the theoretical model of a pneumatic lifting pump is established, and experimental results verify the theoretical model well. The results show that when the submergence ratio is constant, the lifting efficiency decreases with the smaller intake area under different intake areas; and the influences of different holes distributions on liquid flow rate and lifting efficiency are not significant under the same intake area. At the same submergence ratio, the smaller the riser diameter, the smaller the final lifting liquid flow rate and the larger the lifting efficiency peak value.

Towards Understanding Two-Phase Flow Induced Vibration of Piping Structure With Flow Restricting Orifices

2017 ◽  
Author(s):  
Olufemi E. Bamidele ◽  
Wael H. Ahmed ◽  
Marwan Hassan
Keyword(s):  
Flow Pattern ◽  
Flow Rate ◽  
Liquid Flow ◽  
Slug Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Liquid Velocity ◽  
Phase Flow ◽  
Flow Induced Vibration ◽  
Two Phase

The current work studies air-water flow through a ½-inch flow restricting orifice installed in a 1-inch pipe. Investigation of two phase flow downstream the orifice and its effects on vibration of the piping structure have been carried out. Several flow regimes from bubbly to stratified-wavy flow have been analyzed to evaluate the effects of flow pattern, phase redistribution, bubble frequency, and liquid flow rate on the vibration of the structure. The liquid velocity fields have been obtained using Particle Image Velocimetry (PIV) along with post processing algorithm for phase discrimination. Proximity sensors have been used to capture the pipe response in two orthogonal directions. Also, a capacitance sensor was used to measure the two-phase void fraction. The results show that the magnitude and nature of vibrations of the piping structure is largely affected by the frequency and size of the bubbles upstream, vortex creation by pressure fluctuation downstream, liquid flow rate, and the flow pattern upstream. Slug flow and stratified flow patterns induced significant vibrations in the examined structure. The location of the transition region of slug flow on flow pattern maps, play important role in the dynamic response of the structure to the flow.

Liquid Droplet Deposition in Two-Phase Flow

1970 ◽  
Vol 92 (4) ◽  
pp. 587-594 ◽  
Author(s):  
R. Farmer ◽  
P. Griffith ◽  
W. M. Rohsenow
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Liquid Droplet ◽  
Droplet Diameter ◽  
Size Spectrum ◽  
Entrainment Rate ◽  
Phase Flow ◽  
Two Phase

Two-phase annular flow deposition was studied. Experiments were performed to determine where small water droplets in an air stream in a round tube would reach the wall. Results indicated that, for fully accelerated droplets whose diameters were within a factor of two of 150 microns, the number reaching the wall was characteristic of exponential decay with distance downstream. Further, the mean free path to the wall, measured axially, could be taken proportional to droplet diameter. With the assumption that dispersed liquid flow rate in annular two-phase flow regimes consists chiefly of droplets traveling at or near gas velocity, and with arbitrary choices of droplet, diameter spectrum and magnitude of entrainment rate, it was possible to derive analytical expressions for mass transfer coefficient, deposition flow rate, dispersed liquid flow rate, mean diameter and spectrum as they all changed downstream. Some experimental measurements by others were successfully reproduced by these expressions. An important result was that droplet size spectrum “hardening” (preferential depletion of small sizes) operates to decrease the deposition rate downstream, especially if there is no longer any entrainment.

Flow Characteristics of Adiabatic Gas-Liquid Two-Phase Flow in a Horizontal Flat Rectangular Microchannel

2011 ◽  
Author(s):  
Hideo Ide ◽  
Kentaro Satonaka ◽  
Tohru Fukano
Keyword(s):  
Void Fraction ◽  
Slug Flow ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Characteristics ◽  
Flow Patterns ◽  
Phase Flow ◽  
Similar Data ◽  
Two Phase ◽  
The Mean

Experiments were performed to obtain, analyze and clarify the mean void fraction, the mean liquid holdup, and the liquid slug velocity and the air-water two-phase flow patterns in horizontal rectangular microchannels, with the dimensions equal to 1.0 mm width × 0.1 mm depth, and 1.0 mm width × 0.2 mm depth, respectively. The flow patterns such as bubble flow, slug flow and annular flow were observed. The microchannel data showed similar data patterns compared to those in minichannels with the width of 1∼10mm and the depth of 1mm which we had previously reported on. However, in a 1.0 × 0.1 mm microchannel, the mean holdup and the base film thickness in annular flow showed larger values because the effects of liquid viscosity and surface tension on the holdup and void fraction dominate. The remarkable flow characteristics of rivulet flow and the flow with a partial dry out of the channel inner wall were observed in slug flow and annular flow patterns in the microchannel of 0.1 mm depth.

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