Experimental Data Set No. 7: Stratified Flow, Part I: Local Structure

Fabre, J.; Suzanne, C.; Masbernat, Lucien

doi:10.1615/multscientechn.v3.i1-4.120

Cited by 43 publications

(64 citation statements)

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“…Studies that obtained the velocity profiles in the stratified liquid layer were initially performed in rectangular channels [1][2][3][4], and later also in pipes [5][6][7]. These studies showed that when the interfacial drag is absent, or is very low due to the low air velocity, the liquid velocity profile resembles the profile of a Couette-type flow.…”

Section: Introductionmentioning

confidence: 99%

PIV measurements of waves and turbulence in stratified horizontal two-phase pipe flow

Birvalski

Tummers

Delfos

et al. 2014

International Journal of Multiphase Flow

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The technique for obtaining detailed velocity fields in a wavy liquid layer in stratified air/water pipe flow is described in this paper. By combining Particle Image Velocimetry (PIV) with an interface detection technique, the velocity field is resolved in the whole liquid layer. Furthermore, since the shape of the interface is resolved at each time instance, this information is used to conditionally average the velocity field according to the wave phase, which results in phaseresolved velocity profiles. These velocities are then used to separate the wave-induced motion from the turbulenceinduced motion in the liquid layer. In this way, the turbulent wavy regime is analysed. The results of the measurements are compared to the theory of waves and turbulence.

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Section: Introductionmentioning

confidence: 99%

PIV measurements of waves and turbulence in stratified horizontal two-phase pipe flow

Birvalski

Tummers

Delfos

et al. 2014

International Journal of Multiphase Flow

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“…Furthermore, it is worth noting that water average velocity resulting from measured data at probe section (calculated by means of the trapezes rule, thus underestimating the real value) is >4% greater than the value provided in [7] for the water bulk velocity. The same occurs for the air.…”

Section: Experimental Data Understandingmentioning

confidence: 88%

“…A Computational fluid dynamic analysis of a stratified airwater flow experimental investigation performed at the Institut de Mécanique des Fluides de Toulouse in 1985 [7] was performed. The aim was the comprehension of the experimental data and of the role played by some fundamental parameters.…”

Section: Discussionmentioning

confidence: 99%

“…The facility is equipped with sensors located at 7.05 m, 9.10 m, and 11.10 m from the inlet section, which provide the measurements of mass flow rates, local instantaneous water height (by capacitance wire sensors), local mean and fluctuating values of horizontal and vertical velocity components, as well as Reynolds stress tensor (by a laser Doppler anemometer in water and by hot wire anemometer in air). Documentation is available [7] for three test cases conducted at ambient pressure and temperature, characterized by constant water mass flow rate and different air mass flow rates. This work deals only with one of these tests, namely, the "T250" experiment, in which water and air bulk velocities are 0.395 m/s and 3.66 m/s, respectively.…”

Section: Experimental Facility and Testsmentioning

confidence: 99%

“…Complex phenomena take place during this scenario, such as turbulent mixing in the jet region and downstream of the impingement zone, stratified twophase flows, phase change at the steam water interface. This paper deals with the study of a stratified air-water flow experiment performed at the Institut de Mécanique des Fluides de Toulouse in 1985 [7,8]; this flow configuration is likely to share common physical features with the chosen PTS scenario.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

CFD Code Validation against Stratified Air-Water Flow Experimental Data

Terzuoli

Galassi

Mazzini

et al. 2008

Science and Technology of Nuclear Installations

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Pressurized thermal shock (PTS) modelling has been identified as one of the most important industrial needs related to nuclear reactor safety. A severe PTS scenario limiting the reactor pressure vessel (RPV) lifetime is the cold water emergency core cooling (ECC) injection into the cold leg during a loss of coolant accident (LOCA). Since it represents a big challenge for numerical simulations, this scenario was selected within the European Platform for Nuclear Reactor Simulations (NURESIM) Integrated Project as a reference two-phase problem for computational fluid dynamics (CFDs) code validation. This paper presents a CFD analysis of a stratified air-water flow experimental investigation performed at the Institut de Mécanique des Fluides de Toulouse in 1985, which shares some common physical features with the ECC injection in PWR cold leg. Numerical simulations have been carried out with two commercial codes (Fluent and Ansys CFX), and a research code (NEPTUNE CFD). The aim of this work, carried out at the University of Pisa within the NURESIM IP, is to validate the free surface flow model implemented in the codes against experimental data, and to perform code-to-code benchmarking. Obtained results suggest the relevance of threedimensional effects and stress the importance of a suitable interface drag modelling.

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Momentum exchange modeling for coarsely resolved interfaces in a multifield two‐fluid model

Meller

Tekavčič

Krull

et al. 2023

Numerical Methods in Fluids

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Morphology‐adaptive multiphase models are becoming more established for the numerical description of complex gas‐liquid flows adapting dynamically to the local flow morphology. In the present study, two different numerical methods originally designed for distinct flow morphologies are combined, namely the volume‐of‐fluid and the Euler–Euler method. Both edge cases have been proven to be capable of delivering reliable predictions in the respective use cases. The long‐term goal is to improve the prediction of gas‐liquid flows, regardless of the flow regime in a specific application. To capture the system dynamics with a given grid resolution, the flow fields need to be predicted as precise as possible, while the shape of structures such as gas bubbles need to be recovered adequately in topology and shape. The goal is to obtain reliable predictions on intermediate mesh resolutions rather than relying on fine meshes requiring more computational resources. Therefore, a procedure is proposed to locally measure the degree of resolution. With this information, the hydrodynamics in the interface region can be controlled by means of a dedicated interfacial drag formulation in order to improve simulation results across several levels of spatial resolution. A modified formulation of buoyancy is proposed to prevent unphysical oscillations of vertical velocity near a horizontal interface. The functionality is demonstrated in a three‐dimensional case of a gas bubble rising in stagnant liquid and in a co‐current stratified air‐water channel flow in two‐dimensional space. The choice of these different applications demonstrates the general applicability of the proposed model framework.

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Experimental Data Set No. 7: Stratified Flow, Part I: Local Structure

Cited by 43 publications

References 0 publications

PIV measurements of waves and turbulence in stratified horizontal two-phase pipe flow

PIV measurements of waves and turbulence in stratified horizontal two-phase pipe flow

CFD Code Validation against Stratified Air-Water Flow Experimental Data

Momentum exchange modeling for coarsely resolved interfaces in a multifield two‐fluid model

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