scholarly journals Influence of Bubble Deformation on the Signal Characteristics Generated Using an Optical Fiber Gas–Liquid Two-Phase Flow Sensor

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7338
Author(s):  
Yu Ma ◽  
Yangrui Zhang ◽  
Song Li ◽  
Weimin Sun ◽  
Elfed Lewis
Keyword(s):  
Optical Fiber ◽  
Chemical Engineering ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Measurements ◽  
Fiber Probe ◽  
Bubble Deformation ◽  
Wide Range

The use of optical fiber probe in two-phase flow measurements is very frequently encountered, especially in the applications of chemical engineering and petroleum industries. In this work, the influence of bubble piercing signals caused by bubble deformation is studied experimentally using a laboratory-prepared wedge-shaped fiber probe in a lab-scale gas–liquid flow generator. A three-dimensional simulation model is established to study the influence of bubble deformation on the piercing signals. A theoretical analysis of the characteristics of the pre-signal influenced by the bubble deformations is undertaken for a wide range of different modeled bubble shapes. Combining the experimental and simulation results, a promising analytical method to estimate the bubble shapes by analyzing the characteristics of pre-signals is proposed. The results of this investigation demonstrate that it is possible to estimate the bubble shapes before the fiber probe contacts the bubble surface. The method developed in this investigation is therefore highly promising for reducing errors caused by deformation during the probe piercing process.

Development of a Capacitance Based Void Fraction Sensor for Two-Phase Flow Measurements

2013 ◽  
Author(s):  
Rodward L. Hewlin ◽  
John P. Kizito
Keyword(s):  
Void Fraction ◽  
Two Phase Flow ◽  
Full Range ◽  
Working Fluid ◽  
Phase Flow ◽  
Calibration Data ◽  
Two Phase ◽  
Flow Measurements ◽  
Static Calibration ◽  
Wide Range

The aim of this paper was to develop a capacitance based sensor capable of measuring void fraction in a continuous two-phase flow field. The design methodology and operation of the capacitance based void fraction sensor is discussed. Two designs of capacitance void fraction sensors were developed and tested. Some of the problems associated with the first were identified and a new sensor electrode configuration was developed which presented a more sensitive and repeatable response. Data was collected covering a wide range of void fraction measurements ranging from 0 to 1 for water as the working fluid. Calibration of the sensor required that the air gap or void capacitance (dry signal) be measured followed by an increase in liquid levels (wet signal) to obtain a range of void fraction measurements for static calibration. The static calibration data obtained was nonlinear for the full range of void fraction measurements for water. This paper covers the design requirements, calibration procedure and static calibration data obtained for the developed sensor, and dynamic void fraction data measurements. The sensor was tested in both a horizontal and vertical orientation and proved to be orientation insensitive. The experimental results are promising for water and verify successful operation for measuring void fraction in continuous two-phase flows.

Research on Measurement of Void Fraction for Vertically Rising Pipes by Optical Fiber Probe

2011 ◽  
Vol 361-363 ◽  
pp. 671-675 ◽  
Author(s):  
Feng Yun Chen ◽  
Wei Min Liu
Keyword(s):  
Optical Fiber ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Exponential Model ◽  
Phase Flow ◽  
Two Phase ◽  
Cross Sectional ◽  
Fiber Probe ◽  
Optical Fiber Probe ◽  
Oil Gas

A way of measuring the average cross-sectional void fraction for vertically rising oil pipes by using closing valves quickly and optical fiber probe has been researched. Experiments were performed in oil-gas two-phase flow and the range of the average void fraction is 0.1～0.5. The relationship between average cross-sectional void fraction of a oil-gas two-phase flow and pipe’s center void fraction in vertically rising oil pipes, for different pipe diameters and varying oil flow, is obtained. An exponential model of average void fraction is also obtained with reference to Bankoff’s[1] variable density model. It is found that local void fraction reduces from center in radial direction and the local void fraction maximum value appears in the pipe’s center.

Single and two-phase flow measurements using optical fiber Bragg gratings

2014 ◽  
Author(s):  
Virgínia Helena V. Baroncini ◽  
Cicero Martelli ◽  
Marco José da Silva ◽  
Rigoberto E.M. Morales
Keyword(s):  
Optical Fiber ◽  
Two Phase Flow ◽  
Fiber Bragg Gratings ◽  
Bragg Gratings ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Measurements

Time Domain Simulation of the Vibration of a Steam Generator Tube Subjected to Fluidelastic Forces Induced by Two-Phase Cross-Flow

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Téguewindé Sawadogo ◽  
Njuki Mureithi
Keyword(s):  
Steam Generator ◽  
Two Phase Flow ◽  
Work Rate ◽  
Fretting Wear ◽  
Phase Flow ◽  
Reference Case ◽  
Two Phase ◽  
Steam Generator Tube ◽  
Wide Range ◽  
Instability Regime

Having previously verified the quasi-steady model under two-phase flow laboratory conditions, the present work investigates the feasibility of practical application of the model to a prototypical steam generator (SG) tube subjected to a nonuniform two-phase flow. The SG tube vibration response and normal work-rate induced by tube-support interaction are computed for a range of flow conditions. Similar computations are performed using the Connors model as a reference case. In the quasi-steady model, the fluid forces are expressed in terms of the quasi-static drag and lift force coefficients and their derivatives. These forces have been measured in two-phase flow over a wide range of void fractions making it possible to model the effect of void fraction variation along the tube span. A full steam generator tube subjected to a nonuniform two-phase flow was considered in the simulations. The nonuniform flow distribution corresponds to that along a prototypical steam-generator tube based on thermal-hydraulic computations. Computation results show significant and important differences between the Connors model and the two-phase flow based quasi-steady model. While both models predict the occurrence of fluidelastic instability, the predicted pre-instability and post instability behavior is very different in the two models. The Connors model underestimates the flow-induced negative damping in the pre-instability regime and vastly overestimates it in the post instability velocity range. As a result the Connors model is found to underestimate the work-rate used in the fretting wear assessment at normal operating velocities, rendering the model potentially nonconservative under these practically important conditions. Above the critical velocity, this model largely overestimates the work-rate. The quasi-steady model on the other hand predicts a more moderately increasing work-rate with the flow velocity. The work-rates predicted by the model are found to be within the range of experimental results, giving further confidence to the predictive ability of the model. Finally, the two-phase flow based quasi-steady model shows that fluidelastic forces may reduce the effective tube damping in the pre-instability regime, leading to higher than expected work-rates at prototypical operating velocities.

Bias errors induced by cross-talk in two-phase flow measurements

2010 ◽  
Vol 48 (2) ◽  
pp. 250-254 ◽  
Author(s):  
Danxun Li ◽  
Xingkui Wang ◽  
Qiang Zhong
Keyword(s):  
Cross Talk ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Measurements
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