scholarly journals Numerical Experiment on Gas-Solid Two-Phase Flow of Granulation Process in Stirred Vessel (Clarification of Reason Why Double Peaks in Diameter Distribution of Produced Particles Appear)

2007 ◽  
Vol 73 (736) ◽  
pp. 2403-2409
Author(s):  
Tomonori SHINTANI ◽  
Kazuaki INABA ◽  
Makoto YAMAMOTO
Keyword(s):  
Numerical Experiment ◽  
Two Phase Flow ◽  
Diameter Distribution ◽  
Phase Flow ◽  
Two Phase ◽  
Granulation Process ◽  
Stirred Vessel ◽  
Double Peaks

UDV measurements and CFD simulation of two-phase flow in a stirred vessel

2009 ◽  
Vol 9 (6/7) ◽  
pp. 375
Author(s):  
Sanna Haavisto ◽  
Jouni Syrjanen ◽  
Antti Koponen ◽  
Mikko Manninen
Keyword(s):  
Cfd Simulation ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Stirred Vessel

Evaluation and Validation of Two-Phase Flow Numerical Simulations Applied to an Aeronautical Injector Using a Lagrangian Approach

2020 ◽  
Author(s):  
Julien Tillou ◽  
Julien Leparoux ◽  
Jérome Dombard ◽  
Eleonore Riber ◽  
Bénédicte Cuenot
Keyword(s):  
Two Phase Flow ◽  
Operating Conditions ◽  
Spray Angle ◽  
Diameter Distribution ◽  
Phase Flow ◽  
Two Phase ◽  
Experimental Database ◽  
Wall Interaction ◽  
Liquid Mass Flow Rate ◽  
Wall Interactions

Abstract Non-reactive Lagrangian two-phase flow Large-Eddy Simulations (LES) of an industrial aeronautical injector are carried out with the compressible AVBP code and compared with an experimental database in an industrial context. While most of the papers are focused on simplex atomiser with only one fuel passage, we propose to account for specific industrial configurations based on duplex atomiser where both the primary and the secondary passages operate. For the second passage, the fuel spray angle is wider, leading to spray / wall interactions and airblast atomization. The computation domain consists in the experimental mock-up without the fuel atomizer part. The liquid-injection boundary condition is applied through the phenomenological FIM-UR model, which prescribes droplet velocities and diameter distribution at the atomizer tip based on both the atomizer characteristics and the liquid mass flow rate. No specific models are used for spray / wall interaction, and droplets are assumed to slip on the walls. The numerical results are compared with the experimental database for Jet-A1 fuel, built through Phase Doppler Anemometry instrumentation, allowing access to local information regarding the droplets velocity components. Three LES are performed for pressure loss ranging from 1 to 3%, covering an important part of the engine operating conditions, from high altitude relight to cruise operating point. Mean and fluctuating velocity profiles show a relatively good agreement with measurements, for all the operating points. It confirms that the spray/wall interactions, airblast and secondary breakup models may be neglected as a first approximation for configurations where only a relatively small amount of fuel impacts the wall.

Numerical Experiment on Two-Phase Flow Behaviors in Tube Bundle Geometry for Different Mixtures

2017 ◽  
Author(s):  
William Benguigui ◽  
Enrico Deri ◽  
Jerome Lavieville ◽  
Stephane Mimouni ◽  
Elisabeth Longatte
Keyword(s):  
Numerical Experiment ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Tube Bundle ◽  
Phase Flow ◽  
Steam Generators ◽  
Two Phase ◽  
Scale Experiment ◽  
Multi Phase ◽  
Two Fluid

Since steam generators are used, many experiments have been performed to understand the different phenomena appearing in them. One of the main issues to reproduce a similar flow on a reduced-scale experiment is the choice of the two-phase mixture. Air/water and boiling freon are among the most used two-phase flow mixtures. In the present document, a finite-volume CFD code dedicated to multi-phase flows based on a two-fluid approach (extended to n) is used to compare two mixtures numerically. Thanks to two experiments, an air/water horizontal channel and a freon/freon inclined tube bundle, a first part highlights the validity of the two-phase flow modeling. Then, based on inlet superficial velocities from both experiments, a numerical experiment is performed by using each mixture on the other experiment. Void fraction profiles and two-phase flow regimes are compared in order to exhibit the behaviors of both mixtures in a steam generator like tube bundle. Results turn out to provide useful information (void fraction profiles mainly) about mixture properties, and near-wall loads in the vicinity of cylinders are investigated.

Entrainment Into High Speed Air Jet Blowing Out From a Hole to Stagnant Water

2013 ◽  
Author(s):  
Yasuo Koizumi ◽  
Kohei Nago ◽  
Akihiro Uchibori ◽  
Hideki Kamide ◽  
Hiroyuku Ohshima
Keyword(s):  
High Speed ◽  
Open Space ◽  
Two Phase Flow ◽  
Video Camera ◽  
Diameter Distribution ◽  
Phase Flow ◽  
Flow State ◽  
Two Phase ◽  
Air Jet ◽  
Test Vessel

Flow visualization experiments of an air jet in liquid were performed. The test vessel was 270 mm wide, 5 mm depth and 300 mm high. The air jet was blown vertically upward into stagnant liquid in the test vessel from a nozzle of 1 mm wide, 5 mm depth and 20 mm long which was located at the bottom of the test vessel. A flow state of the jet in the liquid was recorded with a high speed video camera at fastest 5×105 f/s. The test liquid was water and kerosene. Experiments were performed at atmospheric pressure and ambient temperature. Filament-like ears and wisps pulled out from the wavy interface were noticed on the interface between liquid and the air jet. The ears and wisps were broken off and entrained into the air jet. The droplets broke up to small entrainments. This process seemed quite similar to the entrainment process in the annular dispersed flow in a pipe. As the air jet velocity increased, the number of entrainments created by the air jet increased lineally and the smaller entrainments increased. The correlation for the entrainment diameter distribution which was developed for the annular dispersed two-phase flow in a pipe predicted well the present results. The correlations for the entrainment diameter developed for entrainments in the annular dispersed two-phase flow in a pipe and for droplets that were blown out into open space above a water pool by a nitrogen gas jet that blew into water vertically upwards considerably underpredicted the experimental results. Measured entrainment rates were considerably lower than the prediction of the correlation for the annular dispersed two-phase flow in a pipe.

Visualization of Entrainment and Surface Behavior of High Speed Air Jet Blowing Out From a Hole to Stagnant Water

2012 ◽  
Author(s):  
Kohei Nago ◽  
Yasuo Koizumi ◽  
Akihiro Uchibori ◽  
Hiroyuki Ohshima
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Droplet Diameter ◽  
Video Camera ◽  
Diameter Distribution ◽  
Phase Flow ◽  
Stagnant Water ◽  
Two Phase ◽  
Air Jet ◽  
Jet Blowing

A two dimensional air jet was blown out from a nozzle into water in a thin vessel. The behavior of the interface between water and the air jet and also the air jet were recorded with a high speed video camera. Filament-like ears and wisps pulled-out from the wavy water surface were noticed in the recorded photos. Droplets are formed from these. Droplet diameters were obtained from the recorded photos. As the air velocity increased, the number of droplets created by the air jet increased lineally and the smaller droplets increased. The correlation for the droplet diameter distribution developed for the annular dispersed two-phase flow in a pipe predicted well the present results. The correlations for the droplet diameter developed for the annular dispersed two-phase flow in a pipe and for the jet blowing out from the stagnant water pool considerably underpredict the experimental results.

scholarly journals Study on Variation Laws of Fluid Threshold Pressure Gradient in Low Permeable Reservoir

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3704
Author(s):  
Mingwei Zhao ◽  
Mengjiao Cao ◽  
Haonan He ◽  
Caili Dai
Keyword(s):  
Pressure Gradient ◽  
Physical Simulation ◽  
Two Phase Flow ◽  
Diameter Distribution ◽  
Phase Flow ◽  
Threshold Pressure ◽  
Power Functions ◽  
Pore Throat ◽  
Two Phase ◽  
Threshold Pressure Gradient

A study on the seepage characteristics and laws of nano-micron pore throat in a low permeable reservoir matrix is of great significance for promoting high efficacy of low permeable reservoirs. Threshold pressure gradient (TPG) is an essential factor to reflect the seepage law. Here, variation laws of TPG and its influencing factors of low reservoir fluid are analyzed systematically through physical simulation experiment. Throat diameter distribution of cores was measured by a mercury injection method, and it was found that with the decrease of pore throat median diameter, TPG increase appeared slowly first and fast afterwards. The patterns of the TPG with permeability in water and oil were compared. Results showed that the TPG versus permeability gave power functions in a form and the TPG in oil was more than two times larger than that of water. Besides, TPG in two-phase flow was investigated by the stabilization method. Tests revealed that the higher the oil saturation, the greater the TPG value, and the TPG in two-phase flow is always higher than that of single-phase flow under the same conditions, which function as the combined action of the capillary force. In addition, the effects of core length, fluid type, and core wettability on the TPG were studied systematically, which has guiding significance for the development of a low permeability reservoir.

Study of Flow Field, Power and Mixing Time in a Two-Phase Stirred Vessel with Dual Rushton Impellers: Experimental Observation and CFD Simulation

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
Ramin Zadghaffari ◽  
Jafarsadegh Moghaddas ◽  
Johan Revstedt
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Mixing Time ◽  
Phase Flow ◽  
Two Phase ◽  
Stirred Vessel ◽  
Image Velocimetry ◽  
Planar Laser ◽  
Computational Fluid Dynamics Cfd

An agitated two-phase flow is studied numerically and experimentally in a mixing vessel agitated with two six-blade Rushton turbines. In Computational Fluid Dynamics (CFD), the full Eulerian multiphase approach coupled with the standard turbulence model is performed to deal with two-phase flow. The impeller rotation was modelled by the Multiple Reference Frame (MRF) approach. The simulation was used to investigate the flow field, power and mixing time in single and two-phase cases. The results of the calculations have been verified with the data that was measured by particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) technique. The predicted results show good agreement with the experimental data. The computational model presented in this study could be useful for explaining the two-phase flow patterns on the mixing process and extending the applications of multiphase stirred reactors.

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