scholarly journals Determination of void fraction in two phase liquid-gas flow using gamma absorption

2016 ◽  
Vol 745 ◽  
pp. 032124 ◽  
Author(s):  
M Zych ◽  
R Hanus ◽  
M Jaszczur ◽  
A Strzępowicz ◽  
L Petryka ◽  
...  
Keyword(s):  
Void Fraction ◽  
Gas Flow ◽  
Two Phase ◽  
Phase Liquid ◽  
Gamma Absorption

scholarly journals Radioisotope measurement of selected parameters of liquid-gas flow using single detector system

2018 ◽  
Vol 180 ◽  
pp. 02124
Author(s):  
Marcin Zych ◽  
Robert Hanus ◽  
Marek Jaszczur ◽  
Volodymyr Mosorov ◽  
Dariusz Świsulski
Keyword(s):  
Void Fraction ◽  
Signal Analysis ◽  
Measurement Errors ◽  
Gas Flow ◽  
Gamma Ray ◽  
Time Delay Estimation ◽  
Dispersed Phase ◽  
Two Phase ◽  
Single Detector

To determine the parameters of two-phase flows using radioisotopes, usually two detectors are used. Knowing the distance between them, the velocity of the dispersed phase is calculated based on time delay estimation. Such a measurement system requires the use of two gamma-ray sealed sources. But in some situations it is also possible to determine velocity of dispersed phase using only one scintillation probe and one gamma-ray source. However, this requires proper signal analysis and prior calibration. This may also cause larger measurement errors. On the other hand, it allows measurements in hard to reach areas where there is often no place for the second detector. Additionally, by performing a previous calibration, it is possible to determine the void fraction or concentration of the selected phase. In this work an autocorrelation function was used to analyze the signal from the scintillation detector, which allowed for the determination of air velocities in slug and plug flows with an accuracy of 8.5%. Based on the analysis of the same signal, a void fraction with error of 15% was determined.

scholarly journals Radioisotope measurements of the liquid-gas flow in the horizontal pipeline using phase method

2018 ◽  
Vol 180 ◽  
pp. 02032
Author(s):  
Robert Hanus ◽  
Marcin Zych ◽  
Marek Jaszczur ◽  
Leszek Petryka ◽  
Dariusz Świsulski
Keyword(s):  
Gas Phase ◽  
Gas Flow ◽  
Spectral Density Function ◽  
Phase Method ◽  
Two Phase ◽  
Cross Spectral Density ◽  
Flow Investigation ◽  
Phase Liquid ◽  
Gamma Absorption ◽  
Classical Cross

The paper presents application of the gamma-absorption method to a two-phase liquid-gas flow investigation in a horizontal pipeline. The water-air mixture was examined by a set of two Am-241 radioactive sources and two NaI(Tl) scintillation probes. For analysis of the electrical signals obtained from detectors the cross-spectral density function (CSDF) was applied. Results of the gas phase average velocity measurements for CSDF were compared with results obtained by application of the classical cross-correlation function (CCF). It was found that the combined uncertainties of the gas-phase velocity in the presented experiments did not exceed 1.6% for CSDF method and 5.5% for CCF.

scholarly journals Determination of cross-sectional void fraction in a two-phase water flow through a PVC pipe

2021 ◽  
Vol 655 (1) ◽  
pp. 012024
Author(s):  
O.H. Ajesi ◽  
M.B. Latif ◽  
S.T. Gbenu ◽  
C. A. Onumejor ◽  
M. K. Fasasi ◽  
...  
Keyword(s):  
Water Flow ◽  
Void Fraction ◽  
Two Phase ◽  
Cross Sectional ◽  
Flow Through ◽  
Pvc Pipe ◽  
Phase Water

Experimental Determination of Single and Two-Phase Cross Flow-Induced Forces on Tube Rows

1988 ◽  
Vol 110 (1) ◽  
pp. 22-28 ◽  
Author(s):  
C. E. Taylor ◽  
M. J. Pettigrew ◽  
F. Axisa ◽  
B. Villard
Keyword(s):  
Spatial Distribution ◽  
Experimental Determination ◽  
Void Fraction ◽  
Mass Flux ◽  
Test Section ◽  
Cross Flow ◽  
Force Coefficient ◽  
Two Phase ◽  
Force Transducers

The fluctuating forces induced by water and air/water cross flow on tube rows with pitch to diameter ratios of 1.5 and 3 were measured. Direct measurement of force spectra was possible because the tube was mounted on force transducers. The tubes within the test section were 300 mm in length and 30 mm in diameter. Results were obtained over ranges of void fraction and mass flux from 0 to 95 percent and 375 to 4125 kg/(m2s), respectively. A reasonably uniform spatial distribution of the void fraction was achieved through the use of an air/water mixing unit. The reported results include the power density spectra of the fluctuating forces and their corresponding force coefficient.

Determination of Two-Phase Flow Void Fraction of R600a in a Horizontal Smooth Tube

2012 ◽  
Author(s):  
Özden Ağra ◽  
Hakan Demir ◽  
Ş. Özgür Atayılmaz ◽  
Ahmet Yurtseven ◽  
A. Selim Dalkılıç ◽  
...  
Keyword(s):  
Neural Network ◽  
Void Fraction ◽  
High Speed ◽  
Saturation Temperature ◽  
Horizontal Tube ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Two Phase ◽  
Void Fractions

In this paper, the void fraction of alternative refrigerant R600a flowing inside horizontal tube is determined by means of an experimental technique, well known correlations in the literature and a generalized neural network analysis. The horizontal tube is made from smooth glass tubing of 4 mm inner diameter. The test runs are done at average saturated condensing temperatures between 30 and 40 °C while the average qualities and the mass fluxes are between 0.45–0.91 and 68.5–138.1 kg m-2s-1 respectively. The flow regime determination inside the tube is performed by means of sight glasses placed at the inlet and outlet sections of the test section, used for in-tube condensation tests, virtually. An image processing technique, performed by means of a high speed camera, is used to determine the void fractions of stratified and annular condensing flow of R600a experimentally. The void fractions are determined using relevant measured data together with 11 different void fraction models and correlations reported in the open literature analytically. Artificial neural network (ANN) analysis is developed to determine the void fractions numerically. For this aim, mass flow rate, average vapor quality, saturation temperature, liquid and vapor densities, liquid and vapor dynamic viscosities and surface tension are selected as the input parameters, while the void fraction is selected as the output. Three-layer network is used for predicting the void fraction. The number of the neurons in the hidden layer was determined by a trial and error process evaluating the performance of the network and standard sensitivity analysis. The measured void fraction values are found to be in good agreement with those from ANN analysis and correlations in the literature. It is also seen that the trained network are more predictive on the determination of void fraction than most of the investigated correlations.

Void Fraction and Vapor and Liquid Temperatures: Local Measurements in Two-Phase Flow Using a Microthermocouple

1973 ◽  
Vol 95 (3) ◽  
pp. 365-370 ◽  
Author(s):  
J. M. Delhaye ◽  
R. Semeria ◽  
J. C. Flamand
Keyword(s):  
Temperature Measurement ◽  
Forced Convection ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Pool Boiling ◽  
Phase Flow ◽  
Subcooled Boiling ◽  
Two Phase ◽  
Local Measurements ◽  
Phase Liquid

A technique is described which enables the detection of the phase (liquid or vapor) in steam-water two-phase flow and the temperature measurement of each phase, using the hot junction of a microthermocouple. The signals are processed with a multichannel analyzer in order to obtain the amplitude histograms of the temperature. Significant results are obtained in pool boiling, forced convection subcooled boiling, and flashing flow of water.

Uncertainty Quantification of Low Void Fraction Measurements Using Wire-Mesh Sensors in Horizontal Air-Water Flows

2016 ◽  
Author(s):  
Étienne M. Lessard ◽  
Robert C. Bowden ◽  
Sun-Kyu Yang
Keyword(s):  
Uncertainty Quantification ◽  
Void Fraction ◽  
Physical Theory ◽  
Gas Flow ◽  
Superficial Velocity ◽  
Wire Mesh ◽  
Flow Loop ◽  
Two Phase ◽  
Flow Measurements ◽  
Void Fractions

The need for a revised methodology and uncertainty quantification for wire-mesh sensor void fraction measurements in horizontal low void fraction flow conditions was identified. Two-phase flow measurements were performed at a low-pressure, adiabatic and horizontal flow loop using wire-mesh sensors over a range of water superficial velocities from 3.5 to 5.5 m/s, air superficial velocities from 0.05 to 0.9 m/s and volumetric void fractions from 1 to 16% Using this proposed analysis, a corrected trend with average percent differences of 36, 21 and 6% was obtained for the low, medium and high gas flow rate cases, respectively, when comparing the wire-mesh sensor void fractions to two-phase pipe flow models. By combining these measurements of the void fraction with those of the interfacial velocity, the gas superficial velocity was calculated based on the physical theory, and compared to the superficial velocity measured by the flowmeters for validation purposes. An estimation of the uncertainty of these parameters showed that most of the measured parameters agreed reasonably with physical theory within 20%.

scholarly journals Axial dispersion of the liquid phase on a three-phase Karr reciprocating plate column

2004 ◽  
Vol 69 (7) ◽  
pp. 581-599 ◽  
Author(s):  
Ljubisa Nikolic ◽  
Vesna Nikolic ◽  
Vlada Veljkovic ◽  
Miodrag Lazic ◽  
Dejan Skala
Keyword(s):  
Liquid Phase ◽  
Gas Flow ◽  
Dispersion Coefficient ◽  
Solid Phase ◽  
Axial Dispersion ◽  
Two Phase ◽  
Three Phase ◽  
Phase Liquid ◽  
Similar Equation ◽  
Plate Column

The influence of the gas flow rate and vibration intensity in the presence of the solid phase (polypropylene spheres) on axial mixing of the liquid phase in a three phase (gas-liquid-solid) Karr reciprocating plate column (RPC) was investigated. Assuming that the dispersionmodel of liquid flow could be used for the real situation inside the column, the dispersion coefficient of the liquid phase was determined as a function of different operating parameters. For a two-phase liquid-solid RPC the following correlation was derived: DL = 1.26(Af)1.42 UL 0.51 ?S 0.23 and a similar equation could be applied with ? 30 % confidence for the calculation of axial dispersion in the case of a three-phase RPC: DL = 1.39(Af)0.47 UL0.42UG0.03 ?S -0.26.

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