Evaluation of Advanced Two-Phase Flow and Combustion Models for Predicting Low Emission Combustors

2000 ◽  
Author(s):  
G. Klose ◽  
R. Schmehl ◽  
R. Meier ◽  
G. Meier ◽  
R. Koch ◽  
...  
Keyword(s):  
Experimental Data ◽  
Two Phase Flow ◽  
Numerical Models ◽  
Computational Method ◽  
Phase Model ◽  
Combustion Model ◽  
Phase Flow ◽  
Two Phase ◽  
Low Emission ◽  
Good Agreement

The development of low emission aero engine combustors strongly depends on the availability of accurate and efficient numerical models. The prediction of the interaction between two-phase flow and chemical combustion is one of the major objectives of the simulation of combustor flows. In this paper, predictions of a swirl stabilized model combustor are compared to experimental data. The computational method is based on an Eulerian two-phase model in conjunction with an Eddy Dissipation (ED) and a presumed-shape-PDF (JPDF) combustion model. The combination of an Eulerian two-phase model with a JPDF combustion model is a novelty. It was found to give good agreement to the experimental data.

Evaluation of Advanced Two-Phase Flow and Combustion Models for Predicting Low Emission Combustors

2000 ◽  
Vol 123 (4) ◽  
pp. 817-823 ◽  
Author(s):  
G. Klose ◽  
R. Schmehl ◽  
R. Meier ◽  
G. Maier ◽  
R. Koch ◽  
...  
Keyword(s):  
Experimental Data ◽  
Two Phase Flow ◽  
Numerical Models ◽  
Computational Method ◽  
Phase Model ◽  
Combustion Model ◽  
Phase Flow ◽  
Two Phase ◽  
Low Emission ◽  
Good Agreement

The development of low-emission aero-engine combustors strongly depends on the availability of accurate and efficient numerical models. The prediction of the interaction between two-phase flow and chemical combustion is one of the major objectives of the simulation of combustor flows. In this paper, predictions of a swirl stabilized model combustor are compared to experimental data. The computational method is based on an Eulerian two-phase model in conjunction with an eddy dissipation (ED) and a presumed-shape-PDF (JPDF) combustion model. The combination of an Eulerian two-phase model with a JPDF combustion model is a novelty. It was found to give good agreement to the experimental data.

scholarly journals Validation of NEPTUNE-CFD Two-Phase Flow Models Using Experimental Data

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Jorge Pérez Mañes ◽  
Victor Hugo Sánchez Espinoza ◽  
Sergio Chiva Vicent ◽  
Michael Böttcher ◽  
Robert Stieglitz
Keyword(s):  
Experimental Data ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Model Parameters ◽  
Phase Flow ◽  
Cfd Model ◽  
Two Phase ◽  
Flow Models ◽  
Phase Models ◽  
Good Agreement

This paper deals with the validation of the two-phase flow models of the CFD code NEPTUNEC-CFD using experimental data provided by the OECD BWR BFBT and PSBT Benchmark. Since the two-phase models of CFD codes are extensively being improved, the validation is a key step for the acceptability of such codes. The validation work is performed in the frame of the European NURISP Project and it was focused on the steady state and transient void fraction tests. The influence of different NEPTUNE-CFD model parameters on the void fraction prediction is investigated and discussed in detail. Due to the coupling of heat conduction solver SYRTHES with NEPTUNE-CFD, the description of the coupled fluid dynamics and heat transfer between the fuel rod and the fluid is improved significantly. The averaged void fraction predicted by NEPTUNE-CFD for selected PSBT and BFBT tests is in good agreement with the experimental data. Finally, areas for future improvements of the NEPTUNE-CFD code were identified, too.

Two-Phase Flow-Induced Forces on Bends in Small Scale Tubes

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
M. F. Cargnelutti ◽  
S. P. C. Belfroid ◽  
W. Schiferli
Keyword(s):  
Experimental Data ◽  
Structural Integrity ◽  
Two Phase Flow ◽  
Experimental Results ◽  
Small Scale ◽  
Phase Flow ◽  
Momentum Exchange ◽  
Two Phase ◽  
Worst Case ◽  
Good Agreement

Two-phase flow occurs in many situations in industry. Under certain circumstances, it can be a source of flow-induced vibrations. The forces generated can be sufficiently large to affect the performance or efficiency of an industrial device. In the worst-case scenario, the mechanical forces that arise may endanger structural integrity. Thus, it is important to take these forces into account in designing industrial machinery to avoid problems during operation. Although the occurrence of such forces is well known, not much is known about their magnitudes because, unfortunately, the amount of experimental data available in literature are rather limited. This paper describes the experiments performed to measure forces in 6 mm diameter tubing containing a bend. Experiments are performed on bends of different radii, with the bend positioned horizontally or vertically. The experimental results are analyzed based on flow regime and bend configuration. A comparison with available experimental results for bigger internal pipe diameter shows a general good agreement. To improve future predictions, a simple model based on momentum exchange is proposed to estimate the forces generated by multiphase flow. The proposed model shows a good agreement with the experimental data.

Mach Number Scaling of Single-Component, Two-Phase Flow

1993 ◽  
Vol 115 (4) ◽  
pp. 772-777
Author(s):  
D. E. Nikitopoulos
Keyword(s):  
Experimental Data ◽  
Mach Number ◽  
Mass Flux ◽  
Two Phase Flow ◽  
Critical Mass ◽  
Critical Flow ◽  
Phase Flow ◽  
Homogeneous State ◽  
Two Phase ◽  
Good Agreement

A simple two-fluid formulation is used to investigate compressibility effects and Mach number scaling for equilibrium, evaporating two-phase flow. The definition of the local two-phase Mach number emerges from a critical flow analysis. Comparisons of the theoretical critical mass flux with existing experimental data obtained in steam-water flows show very good agreement for moderate and high qualities over a wide critical pressure range. Within this quality range the predicted critical mass flux is quite insensitive to the velocity ratio. The analysis confirms previous observations, based on homogeneous flow models, indicating that in variable area ducts the critical state does not occur at a geometrical throat. Results of existing critical flow experiments in slowly diverging ducts are discussed in the light of this conclusion. A way from the neighborhood of the flash horizon, pressure-drop and kinetic energy changes are shown to scale with similar local Mach functions as those of single-phase compressible flow. Existing experimental data from vertical-upwards and horizontal two-phase flows in pipes indicate that the Mach number calculated on the basis of the local homogeneous state provides the optimum scaling performance. Scaling of the same experimental data using a Mach number based on the local nonhomogeneous state provides results that are in reasonably good agreement with the theoretical scaling guidelines and predictions, but is handicapped by considerable scatter in the scaled experimental variables.

Average Volumetric Concentration in Two-Phase Flow Systems

1965 ◽  
Vol 87 (4) ◽  
pp. 453-468 ◽  
Author(s):  
N. Zuber ◽  
J. A. Findlay
Keyword(s):  
Experimental Data ◽  
Two Phase Flow ◽  
Weighted Average ◽  
Phase Flow ◽  
Nonuniform Flow ◽  
Volumetric Concentration ◽  
Two Phase ◽  
Wide Pressure Range ◽  
Wide Pressure ◽  
Good Agreement

A general expression which can be used either for predicting the average volumetric concentration or for analyzing and interpreting experimental data is derived. The analysis takes into account both the effect of nonuniform flow and concentration profiles as well as the effect of the local relative velocity between the phases. The first effect is taken into account by a distribution parameter, whereas the latter is accounted for by the weighted average drift velocity. Both effects are analyzed and evaluated. The results predicted by the analysis are compared with experimental data obtained for various two-phase flow regimes, with various liquid-gas mixtures in adiabatic, vertical flow over a wide pressure range. Good agreement with experimental data is shown.

Two-Phase Flow Patterns in a Square Micro-Channel

2003 ◽  
Author(s):  
Jian-Fu Zhao ◽  
Bin Li
Keyword(s):  
Experimental Data ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Bond Number ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase ◽  
Scale Modeling ◽  
Order Of Magnitude ◽  
Good Agreement

A new set of experimental data of two-phase air-water flow patterns in a square micro-channel is presented. The channel has a cross-section of 1×1 mm2 and a length of 300 mm. The ranges of the gas and liquid superficial velocities are 0.1–10 m/s and 0.2–7 m/s, respectively. Bubble, bubbleslug transitional, slug, and frothy patterns are observed. The present data are compared with other experimental data reported in the literature, and a good agreement is obtained. It is also compared the present data with those obtained from reduced gravity experiments, in which the Bond number has the same order of magnitude. Some problems associated with the micro-scale modeling of microgravity two-phase flow are also discussed.

Upward Vertical Two-Phase Flow Through an Annulus—Part II: Modeling Bubble, Slug, and Annular Flow

1992 ◽  
Vol 114 (1) ◽  
pp. 14-30 ◽  
Author(s):  
E. F. Caetano ◽  
O. Shoham ◽  
J. P. Brill
Keyword(s):  
Flow Pattern ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Bubble Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through ◽  
Physical Phenomena ◽  
Good Agreement

Mechanistic models have been developed for each of the existing two-phase flow patterns in an annulus, namely bubble flow, dispersed bubble flow, slug flow, and annular flow. These models are based on two-phase flow physical phenomena and incorporate annulus characteristics such as casing and tubing diameters and degree of eccentricity. The models also apply the new predictive means for friction factor and Taylor bubble rise velocity presented in Part I. Given a set of flow conditions, the existing flow pattern in the system can be predicted. The developed models are applied next for predicting the flow behavior, including the average volumetric liquid holdup and the average total pressure gradient for the existing flow pattern. In general, good agreement was observed between the experimental data and model predictions.

scholarly journals Experimental data for the slug two-phase flow characteristics in horizontal pipeline

Data in Brief ◽  
2018 ◽  
Vol 16 ◽  
pp. 527-530 ◽  
Author(s):  
Abdalellah O. Mohmmed ◽  
Mohammad S. Nasif ◽  
Hussain H. Al-Kayiem
Keyword(s):  
Experimental Data ◽  
Two Phase Flow ◽  
Flow Characteristics ◽  
Phase Flow ◽  
Two Phase

scholarly journals Investigation of representing hysteresis in macroscopic models of two-phase flow in porous media using intermediate scale experimental data

2017 ◽  
Vol 53 (1) ◽  
pp. 199-221 ◽  
Author(s):  
Abdullah Cihan ◽  
Jens Birkholzer ◽  
Luca Trevisan ◽  
Ana Gonzalez-Nicolas ◽  
Tissa Illangasekare
Keyword(s):  
Experimental Data ◽  
Porous Media ◽  
Two Phase Flow ◽  
Flow In Porous Media ◽  
Phase Flow ◽  
Two Phase ◽  
Intermediate Scale ◽  
Macroscopic Models

Effect of Common Impurities on the Phase Behavior of Carbon-Dioxide-Rich Systems: Minimizing the Risk of Hydrate Formation and Two-Phase Flow

SPE Journal ◽  
2011 ◽  
Vol 16 (04) ◽  
pp. 921-930 ◽  
Author(s):  
Antonin Chapoy ◽  
Rod Burgass ◽  
Bahman Tohidi ◽  
J. Michael Austell ◽  
Charles Eickhoff
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Phase Behavior ◽  
Water Content ◽  
Thermodynamic Model ◽  
Two Phase Flow ◽  
Hydrate Formation ◽  
Experimental Methodology ◽  
Phase Flow ◽  
Two Phase

Summary Carbon dioxide (CO2) produced by carbon-capture processes is generally not pure and can contain impurities such as N2, H2, CO, H2 S, and water. The presence of these impurities could lead to challenging flow-assurance issues. The presence of water may result in ice or gas-hydrate formation and cause blockage. Reducing the water content is commonly required to reduce the potential for corrosion, but, for an offshore pipeline system, it is also used as a means of preventing gas-hydrate problems; however, there is little information on the dehydration requirements. Furthermore, the gaseous CO2-rich stream is generally compressed to be transported as liquid or dense-phase in order to avoid two-phase flow and increase in the density of the system. The presence of impurities will also change the system's bubblepoint pressure, hence affecting the compression requirement. The aim of this study is to evaluate the risk of hydrate formation in a CO2-rich stream and to study the phase behavior of CO2 in the presence of common impurities. An experimental methodology was developed for measuring water content in a CO2-rich phase in equilibrium with hydrates. The water content in equilibrium with hydrates at simulated pipeline conditions (e.g., 4°C and up to 190 bar) as well as after simulated choke conditions (e.g., at -2°C and approximately 50 bar) was measured for pure CO2 and a mixture of 2 mol% H2 and 98 mol% CO2. Bubblepoint measurements were also taken for this binary mixture for temperatures ranging from -20 to 25°C. A thermodynamic approach was employed to model the phase equilibria. The experimental data available in the literature on gas solubility in water in binary systems were used in tuning the binary interaction parameters (BIPs). The thermodynamic model was used to predict the phase behavior and the hydrate-dissociation conditions of various CO2-rich streams in the presence of free water and various levels of dehydration (250 and 500 ppm). The results are in good agreement with the available experimental data. The developed experimental methodology and thermodynamic model could provide the necessary data in determining the required dehydration level for CO2-rich systems, as well as minimum pipeline pressure required to avoid two-phase flow, hydrates, and water condensation.

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