Sudden Contraction Losses in Two-Phase Flow

1966 ◽  
Vol 88 (1) ◽  
pp. 1-8 ◽  
Author(s):  
G. E. Geiger ◽  
W. M. Rohrer
Keyword(s):  
Mass Velocity ◽  
Two Phase Flow ◽  
Homogeneous Model ◽  
Area Ratio ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Models ◽  
System Pressure ◽  
Sudden Contraction

The experimentally determined pressure drops due to a sudden contraction in two-phase flow in round pipes is given as a function of system pressure, flowing mixture quality, contraction area ratio, and mass velocity. The theoretical equation derived for the resulting pressure drop is ΔPc=G322gcρ¯[1−σ2+K¯TPC] where KTPC is a parameter independent of mass velocity. This parameter was evaluated for three different two-phase flow models. It is shown that the fog-flow (homogeneous) model gives the best correlation of data over the whole range of conditions studied. The range of pressures studied was 200–500 psia; the area ratios varied from 0.144 to 0.398; the mass velocity varied from 0.52 × 106 to 4.82 × 106 lb/hr-ft2. The fluid used in this study was water.

Experimental and Analytical Studies on Frictional Pressure Drops of Gas-Liquid Two-Phase Flow at Vena Contract and Expansion

2008 ◽  
Author(s):  
Hiroyasu Ohtake ◽  
Masato Hagiwarai ◽  
Yasuo Koizumi
Keyword(s):  
Pressure Loss ◽  
Two Phase Flow ◽  
Test Tube ◽  
Experimental Results ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Pressure Losses ◽  
Sudden Contraction ◽  
Sudden Enlargement

The frictional pressure drops of gas-liquid two-phase flow in mini-micro pipes and at vena contract and expansion were investigated experimentally and analytically. Pressure drops of straight pipe, sudden enlargement and sudden contraction of gas-liquid two-phase flow in mini-pipes were measured. Test liquid was water at room temperature; test gas was argon. The diameter of the test mini-pipe was 1.0 and 0.5 mm, respectively. Each test tube was connected at both ends to small tanks. The diameter of the small tank was 15 mm for 1.0 mm diameter of test tube and 5 mm for 0.5 mm diameter of test tube, respectively. Thus, the cross-sectional ratio of the contraction was about 1000; the ratio of the enlargement was about 0.001. The pressure drop data were collected over 3.0 < UG < 130 m/s for the superficial gas velocity and 0.02 < UL < 6.0 m/s for the superficial liquid velocity. The present experimental results of sudden contraction pressure loss factor Kc and sudden enlargement pressure loss factor Ke of single-phase liquid flow in mini-pipes differed from the conventional values, Kc = 0.5 and Ke = 1.0. The calculated results by using a commercial code, STAR-CD, agreed with the present experimental results for mini-pipes. Assuming to homogenous flow and incompressible flow, sudden contraction pressure loss, sudden enlargement pressure loss and their factors Kc, Ke for gas-liquid two-phase flow were estimated by using momentum equation and energy equation. The contraction pressure losses by Hewitt’s correlation for conventional pipes were similar to the present experimental results of the contraction for mini-circular pipe. Collier’s correlation of the enlargement pressure loss for conventional pipes underpredicted the present experimental results of the enlargement for mini-tube. Based on the present experimental results, new correlations were obtained for the enlargement and the contraction pressure losses in mini-channel.

scholarly journals Study Pressure Drop for Two-Phase Flow in a Large Diameter Tube

2019 ◽  
Vol 17 (72) ◽  
pp. 101-109
Author(s):  
Muhsen Koli Nahi
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Homogeneous Model ◽  
Large Diameter ◽  
Horizontal Tube ◽  
Phase Flow ◽  
Water Mixture ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Pressure

The aim of this study is to discover the deviation of two phase flow correlations. A comparsion was made between the expermital values of two-phase flow pressure drops data were obtained experimentally by Al-Jumaily (1999) by using air-water mixture in a horizontal tube of (132 mm) nominal diameter and a test section of (32 m) long at pressure and temperature close to atmospheric and those predicted by three correlations well-used in the literature, which show that the homogeneous model was the best

Experimental and Analytical Studies on Frictional Pressure Drops of Gas-Liquid Two-Phase Flow in Mini-Micro Pipes and at Vena Contract and Expansion

2007 ◽  
Author(s):  
Hiroyasu Ohtake ◽  
Hideyasu Ohtaki ◽  
Masato Hagiwara ◽  
Yasuo Koizumi
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Liquid Velocity ◽  
Experimental Results ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Frictional Pressure Drop ◽  
Sudden Contraction ◽  
Sudden Enlargement

The frictional pressure drops of gas-liquid two-phase flow in mini-micro pipes and at vena contract and expansion were investigated experimentally and analytically. Pressure drops of straight pipe, sudden enlargement and sudden contraction of gas-liquid two-phase flow in mini-pipes were measured. Test liquid was water at room temperature; test gas was argon. The diameter of the test mini-pipe was 0.5, 0.25 and 0.12 mm, respectively; the length was 500, 250 and 50 mm, respectively. The cross-sectional ratio of the contraction was about 1000; the ratio of the enlargement was about 0.001. The pressure drop data and the flow pattern were collected over 3.0 &lt; UG &lt; 130 m/s for the superficial gas velocity and 0.02 &lt; UL &lt; 6.0 m/s for the superficial liquid velocity. The two-phase friction multiplier data for D &gt; 0.5 mm showed to be in good agreement with the conventional correlations. On the other hand, the two-phase friction multiplier data for D &lt; 0.25 mm differed from the calculated values by the conventional correlations. Then, thickness of liquid film around a gas plug and size of gas core were estimated and the effect of frictional pressure drop on channel size was discussed through Knudsen Number of gas and instability on liquid-gas interface. Namely, the effect of mini-pipe was rarefaction effects, Kn&lt;0.1. New correlation of frictional pressure drop of gas-liquid two-phase flow is proposed for mini pipes. The coefficients of sudden enlargement and sudden contraction in mini-pipes for the gas-water two-phase flow were modified from the present experimental results. The experimental results were also examined through numerical simulation by a commercial code.

scholarly journals Momentum Flux in Two-Phase Flow

1968 ◽  
Vol 90 (2) ◽  
pp. 211-220 ◽  
Author(s):  
G. B. Andeen ◽  
P. Griffith
Keyword(s):  
Velocity Profile ◽  
Steady Flow ◽  
Momentum Flux ◽  
Two Phase Flow ◽  
Homogeneous Model ◽  
Phase Flow ◽  
Slip Model ◽  
Two Phase ◽  
Flow Models

Measurements of the momentum flux through a section of pipe with steam-water and air-water two-phase flow are reported. The results are used to evaluate the utility of various two-phase flow models and the underlying assumptions. The slip model was found to yield low values. The homogeneous model correlated the data well, but this is because of compensating errors in the assumptions. The steady flow assumption of most two-phase flow models is considered to be inadequate for prediction of the momentum flux at low quality. At higher quality the velocity profile is the dominant consideration.

scholarly journals Port-Hamiltonian formulation of two-phase flow models

2021 ◽  
Vol 149 ◽  
pp. 104881
Author(s):  
H. Bansal ◽  
P. Schulze ◽  
M.H. Abbasi ◽  
H. Zwart ◽  
L. Iapichino ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Hamiltonian Formulation ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Models

scholarly journals Simulation of the two-phase flow across tube bundle

2021 ◽  
Vol 2088 (1) ◽  
pp. 012031
Author(s):  
Hossein Abdi ◽  
O I Melikhov ◽  
V I Melikhov
Keyword(s):  
Mass Velocity ◽  
Two Phase Flow ◽  
Tube Bundle ◽  
Diameter Ratio ◽  
Phase Flow ◽  
Rod Bundles ◽  
Two Phase ◽  
Horizontal Steam Generator ◽  
Gamma Densitometer ◽  
Hydraulic Processes

Abstract Experiments on two-phase flow across an in-line tube bundle are analyzed with the STEG code, which has been developed for modeling thermal-hydraulic processes in a horizontal steam generator (SG). An adiabatic, vertical two-phase flows of air-water across horizontal in-line, 5 x 20 rod bundles, with a pitch-to-diameter ratio P/D=1.3 are considered, the mass velocity is varied in the range 27 - 818 kg/m2s. The calculated values of void fraction in the tube bundle are compared with the experimental ones measured by a gamma densitometer. A reasonable agreement between the calculations and the experimental data is obtained.

Homogeneous two-phase flow models and accurate steam-water table look-up method for fast transient simulations

2017 ◽  
Vol 95 ◽  
pp. 199-219 ◽  
Author(s):  
M. De Lorenzo ◽  
Ph. Lafon ◽  
M. Di Matteo ◽  
M. Pelanti ◽  
J.-M. Seynhaeve ◽  
...  
Keyword(s):  
Water Table ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Models ◽  
Transient Simulations ◽  
Fast Transient

scholarly journals DYNAMICS OF TWO-PHASE FLOW ACROSS HORIZONTAL TUBE BUNDLES - A REVIEW

2005 ◽  
Vol 4 (2) ◽  
Author(s):  
G. Ribatskia ◽  
J. R. Thome
Keyword(s):  
Void Fraction ◽  
Two Phase Flow ◽  
Experimental Studies ◽  
Horizontal Tube ◽  
Prediction Methods ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Frictional Pressure Drop ◽  
Tube Bundles

This paper presents a state-of-the-art review of the hydrodynamic aspects of two-phase flow across horizontal tube bundles. The review covers studies related to the evaluation of void fraction, two-phase flow behaviors and pressure drops on the shell side of staggered and in-line tube bundles for upward, downward and side-to-side flows. This study of the literature critically describes the proposed flow pattern maps and semi-empirical correlations for predicting void fraction and frictional pressure drop. These predicting methods are generally based on experimental results for adiabatic air-water flows. A limited number of experimental studies with R-11 and R-113 were also carried out in the past. The review shows noticeable discrepancies among the available prediction methods. Finally, this study suggests that further research focusing on the development of representative databanks and new prediction methods is still necessary.

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