21219 Study on pressure loss of two phase flow in mini pipes and at sudden expansion and contraction

2008 ◽  
Vol 2008.14 (0) ◽  
pp. 331-332
Author(s):  
Hiroyasu OHTAKE ◽  
Masato HAGIWARA ◽  
Yasuo KOIZUMI
Keyword(s):  
Pressure Loss ◽  
Two Phase Flow ◽  
Sudden Expansion ◽  
Phase Flow ◽  
Two Phase

Characteristics of Air-Oil Two-Phase Flow Across a Sudden Expansion

2003 ◽  
Author(s):  
W. H. Ahmed ◽  
C. Y. Ching ◽  
M. Shoukri
Keyword(s):  
Void Fraction ◽  
Two Phase Flow ◽  
Pressure Recovery ◽  
Sudden Expansion ◽  
Phase Flow ◽  
Sudden Increase ◽  
Two Phase ◽  
Recovery Coefficient ◽  
Dynamic Head ◽  
Experimental Pressure

The pressure recovery and void fraction change of air-oil two-phase flow across a sudden expansion has been investigated experimentally over a range of flow conditions. The pressure upstream and downstream of a half-inch to one-inch sudden expansion was measured using a series of pressure taps, and capacitance sensors were used to measure the void fraction along the test section. The void fraction increases as the flow approaches the sudden expansion section, with a sudden increase immediately downstream of the expansion followed by a gradual relaxation to the fully developed value further downstream. The normalized pressure recovery coefficient using the dynamic head based on the homogeneous density and two-phase velocity is found to collapse when plotted as a function of the mass quality. The experimental pressure recovery data are compared with predictions from existing models, and are found to be in good agreement with the Delhaye model with the void fraction relation of Wallis.

scholarly journals Sudden Expansion of Gas-solid Two Phase flow

1982 ◽  
Vol 25 (200) ◽  
pp. 190-195 ◽  
Author(s):  
Kiyoaki DEGUCHI ◽  
Hiroyuki TASHIRO ◽  
Tomosada JOTAKI ◽  
Yuji TOMITA
Keyword(s):  
Two Phase Flow ◽  
Sudden Expansion ◽  
Phase Flow ◽  
Two Phase

B208 A Study on Multi-dimensional Behavior of Gas-Liquid Two-Phase Flow in Round Tube with Sudden Expansion Part.

2001 ◽  
Vol 2001 (0) ◽  
pp. 395-396
Author(s):  
Koichi KONDO ◽  
Kenji YOSHIDA ◽  
Tadayoshi MATSUMOTO ◽  
Tomio OKAWA ◽  
Isao KATAOKA
Keyword(s):  
Two Phase Flow ◽  
Sudden Expansion ◽  
Phase Flow ◽  
Round Tube ◽  
Two Phase

Field-Scale Evaluation of Leak Detection for Gas-Liquid Two-Phase Flow in Deepwater Production Systems

2005 ◽  
Author(s):  
John M. Griffin ◽  
John Rogers Smith
Keyword(s):  
Pressure Loss ◽  
Two Phase Flow ◽  
Production Systems ◽  
Average Rate ◽  
Theoretical Method ◽  
Internal Diameter ◽  
Phase Flow ◽  
Field Scale ◽  
Flow Loop ◽  
Two Phase

This paper focuses on validating a theoretical method for the detection of leaks in deep water, multi-phase pipelines. [1] Six field-scale, two-phase flow tests were conducted to compare small leaks with a no-leak condition. These tests qualitatively demonstrate the feasibility of Scott’s concept. Knowing the characteristic pressure loss versus throughput in a line without a leak provides a basis for determining the presence of a leak by measuring pressure loss and flowrate out of the line. If the pressure loss is higher than expected for that flowrate, a leak is a likely possible cause. In these full-scale tests, a leak was readily detectable once the leak rate exceeded 16 percent for the case where the average rate exiting the line was 547 MCFPD. These tests were performed on a 3.64 inch (9.25 cm) internal diameter 9,640 foot (2,938 m) long flow loop with the leak occurring at the midpoint.

Measurement of Pressure Loss Throughout a Clogged Steam Generator Tube Support Plate in Single Phase Flow

2010 ◽  
Author(s):  
Olivier Brunin ◽  
Geoffrey Deotto ◽  
Franck David ◽  
Joe¨l Pillet ◽  
Gilles Dague ◽  
...  
Keyword(s):  
Pressure Loss ◽  
Single Phase ◽  
Experimental Approach ◽  
Two Phase Flow ◽  
Loss Coefficient ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Steam Generators ◽  
Two Phase ◽  
Pressure Loss Coefficient

After a period of several years of operation, steam generators can be affected by fouling and clogging. Fouling means that deposits of sludge accumulate on tubes or tube support plates (TSP). That results in a reduction of heat exchange capabilities and can be modelled by means of a fouling factor. Clogging is a reduction of flow free area due to an accumulation of sludge in the space between TSP and tubes. The increase of the clogging ratio results in an increase of the overall TSP pressure loss coefficient. The link between the clogging ratio and the overall TSP pressure loss coefficient is the most important aspect of our capability to accurately calculate the thermal-hydraulics of clogged steam generators. The aim of the paper is to detail the experimental approach chosen by EDF and AREVA NP to address the calculation uncertainties. The calculation method is classically based on the computation of a single-phase (liquid-only) pressure loss coefficient, which is multiplied by a two-phase flow factor. Both parameters are well documented and can be derived on the basis of state of the art methods such as IDEL’CIK diagrams and CHISHOLM formula. The experimental approach consists of a validation of the correlations by performing tests on a mock-up section with an upward flow throughout a vertical array of tubes. A mixture of water and vapour refrigerant R116 is used to represent two-phase flows. The tube bundle is composed of a 25 tubes array in a square arrangement. The overall height of the mock-up is 2 m. Eight test TSPs were manufactured, considering eight different clogging configurations: six plates with a typical clogging profile at six clogging ratios (0, 44%, 58%, 72%, 86%, 95%), and two plates with a clogging ratio of 72% associated with two different clogging profiles (large bending radius profile and rectangular profile). A series of tests were performed in 2009 in single-phase flow conditions. Two-phase flow tests with a mixture of liquid water and vapour refrigerant R116 will be performed in 2010. The paper illustrates the main results obtained during the single-phase tests performed in 2009.

Effects of Curved Section on Gas-Liquid Two-Phase Flow in Milli-Channel

2013 ◽  
Author(s):  
Kazuki Takeda ◽  
Shinpei Okamoto ◽  
Kenji Yoshida ◽  
Isao Kataoka
Keyword(s):  
Pressure Loss ◽  
High Speed ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Narrow Channel ◽  
Phase Flow ◽  
Straight Section ◽  
Industrial Products ◽  
Two Phase ◽  
Curved Section

In recent years, we can easily find the gas-liquid two-phase flow in narrow channel which has straight section and curved section in many industrial products. In order to improve the performance of these industrial products, it is important to clarify the effects of curved section on gas-liquid two-phase flow behavior in narrow channel. In this study, we have measured the pressure loss precisely on straight section and curved section in milli-channel respectively. From the measured pressure loss, we evaluated the mean pressure loss and its intensity. Flow visualization by using high-speed video camera was additionally performed to make clear the relation between modification of pressure loss and flow pattern in curved section. As a result, effects of curved section on gas-liquid two-phase flow in narrow channel were evaluated.

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