Local Liquid Velocity in Vertical Air-Water Downward Flow

2004 ◽  
Vol 126 (4) ◽  
pp. 539-545 ◽  
Author(s):  
Xiaodong Sun ◽  
Sidharth Paranjape ◽  
Seungjin Kim ◽  
Hiroshi Goda ◽  
Mamoru Ishii ◽  
...  
Keyword(s):  
Liquid Flow ◽  
Liquid Velocity ◽  
Laser Doppler Anemometry ◽  
Two Phase ◽  
Downward Flow ◽  
Flow Rates ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Local Measurements ◽  
Flux Model

This paper presents an experimental study of local liquid velocity measurement in downward air-water bubbly and slug flows in a 50.8 mm inner-diameter round pipe. The axial liquid velocity and its fluctuations were measured by a laser Doppler anemometry (LDA) system. It was found that the maximum liquid velocity in a downward two-phase flow could occur off the pipe centerline at relatively low liquid flow rates and this observation is consistent with other researchers’ results. The comparisons between the liquid flow rates measured by a magnetic flow meter and those obtained from the local LDA and multi-sensor conductivity probe measurements showed good agreement. In addition, based on the local measurements the distribution parameter and the drift velocity in the drift-flux model were obtained for the current downward flow tests.

Local Liquid Velocity in Vertical Air-Water Bubbly Downward Flow

2003 ◽  
Author(s):  
Xiaodong Sun ◽  
Sidharth Paranjape ◽  
Seungjin Kim ◽  
Hiroshi Goda ◽  
Mamoru Ishii ◽  
...  
Keyword(s):  
Liquid Velocity ◽  
Laser Doppler Anemometry ◽  
Downward Flow ◽  
Drift Flux Model ◽  
Local Characteristics ◽  
Drift Flux ◽  
Local Measurements ◽  
Flux Model ◽  
Local Conductivity ◽  
Inner Diameter

Local characteristics of the liquid phase in downward air-water bubbly and slug flows were investigated in a 50.8-mm inner-diameter round pipe. A laser Doppler anemometry system was used to measure axial liquid velocity and its fluctuations. To reduce the measurement uncertainty, the experiments were performed in flow conditions with low void fraction. The comparisons between the liquid flow rates measured by the magnetic flow meter and those obtained from the local measurements showed good agreements. In addition, based on the LDA measurements and the data acquired by the local conductivity probes, the local relative velocity distribution, the distribution parameter and the drift velocity in the drift-flux model were obtained for the current downward flow.

Investigation of a Two-Phase Siphon: Pressure Drop Characteristics, Flow Prediction, and Flow Regime Change Prediction

Volume 3 ◽  
2004 ◽  
Author(s):  
J. Howard Arthur ◽  
Charles D. Morgan ◽  
Cory D. Engelhard ◽  
Berton Austin
Keyword(s):  
Pressure Drop ◽  
Flow Regime ◽  
Distribution Parameter ◽  
Regime Transition ◽  
Two Phase ◽  
Flow Rates ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Flow Regime Transition ◽  
Flux Model

In some nuclear power plants, a passive siphon breaking system is used to prevent the spent fuel tank from draining in the event of a break in the vertical leg of the heat exchanger piping. A hole is drilled in the horizontal leg of the piping. When the water level in the tank drops below the pipe level air is sucked into the system. When sufficient air is entrained in the pipe the siphon will break. A model to predict the flow rate in a vertical siphon was developed in reference 1 using the homogeneous flow model. The predicted flow rates were greater than measured flow rates. In order to improve the predictive capability, pressure drop measurements were obtained from ten foot vertical test sections with nominal diameters of 0.5, 0.75, 1.0, 1.25, 1.5, and 2.0 inches. Values of the distribution parameter, Co, for the drift flux model were determined from the pressure drop data. When the model of reference 1 is changed from homogeneous flow to drift flux model with the distribution parameter determined from the pressure drop data, good agreement with measured liquid flow rates is obtained. The improved model, along with the correlation for the siphon break condition obtained provides a good method for determining the hole size required to break the siphon. There is a paucity of data for two-phase flow regime transition where the flow is in the downward direction that is typical in a siphon. Flow regime transition data were obtained using the test sections listed above. The flow map of Oshinowo2 et al. gave a reasonable prediction of the transition from bubbly to slug flow. None of the references investigated gave an adequate prediction of the point where the siphon would break. A correlation for the siphon break point was developed.

Interfacial Structures and Regime Transition in Co-Current Downward Bubbly Flow

2004 ◽  
Vol 126 (4) ◽  
pp. 528-538 ◽  
Author(s):  
S. Kim ◽  
S. S. Paranjape ◽  
M. Ishii ◽  
J. Kelly
Keyword(s):  
Two Phase Flow ◽  
Bubbly Flow ◽  
Superficial Velocity ◽  
Phase Flow ◽  
Two Phase ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Flow Parameters ◽  
Interfacial Structures ◽  
Flux Model

The vertical co-current downward air-water two-phase flow was studied under adiabatic condition in round tube test sections of 25.4-mm and 50.8-mm ID. In flow regime identification, a new approach was employed to minimize the subjective judgment. It was found that the flow regimes in the co-current downward flow strongly depend on the channel size. In addition, various local two-phase flow parameters were acquired by the multi-sensor miniaturized conductivity probe in bubbly flow. Furthermore, the area-averaged data acquired by the impedance void meter were analyzed using the drift flux model. Three different distributions parameters were developed for different ranges of non-dimensional superficial velocity, defined by the ration of total superficial velocity to the drift velocity.

One-dimensional drift-flux model for two-phase flow in pool rod bundle systems

2012 ◽  
Vol 40 ◽  
pp. 166-177 ◽  
Author(s):  
Shao-Wen Chen ◽  
Yang Liu ◽  
Takashi Hibiki ◽  
Mamoru Ishii ◽  
Yoshitaka Yoshida ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Rod Bundle ◽  
Flux Model

scholarly journals A Hydraulic Model for Multiphase Flow Based on the Drift Flux Model in Managed Pressure Drilling

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3930 ◽  
Author(s):  
Fang ◽  
Meng ◽  
Wei ◽  
Xu ◽  
Li
Keyword(s):  
Multiphase Flow ◽  
Oil And Gas ◽  
Splitting Method ◽  
Field Application ◽  
Effective Control ◽  
Two Phase ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Managed Pressure Drilling ◽  
Flux Model

Managed pressure drilling (MPD) is a drilling technique used to address the narrow density window under complex geological environments. It has widespread applications in the exploration and exploitation of oil and gas, both onshore and offshore. In this study, to achieve effective control of the downhole pressure to ensure safety, a gas–liquid two-phase flow model based on the drift flux model is developed to describe the characteristics of transient multiphase flow in the wellbore. The advection upwind splitting method (AUSM) numerical scheme is used to assist with calculation and analysis, and the monotonic upwind scheme for conservation laws (MUSCLs) technique with second-order precision is adopted in combination with the Van Leer slope limiter to improve precision. Relevant data sourced from prior literature are used to validate the suggested model, the results of which reveal an excellent statistical consistency. Further, the influences of various parameters in a field application, including backpressure, density, and mass flow, are analyzed. Over the course of later-stage drilling, a combination of wellhead backpressure and displacement is recommended to exercise control.

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