Research on Low Water Volume Fraction Measurement of Two-Phase Flow Based on TM010 Mode Microwave Cavity Sensor

2019 ◽  
Author(s):  
Yi-Guang Yang ◽  
Ying Xu ◽  
Tao Zhang
Keyword(s):  
Two Phase Flow ◽  
Volume Fraction ◽  
Microwave Cavity ◽  
Water Volume ◽  
Phase Flow ◽  
Two Phase ◽  
Water Volume Fraction ◽  
Fraction Measurement

Water Volume Fraction Estimation in Two-Phase Flow Based on Electrical Capacitance Tomometry

2018 ◽  
Vol 18 (16) ◽  
pp. 6822-6835 ◽  
Author(s):  
Francisco R. Moreira da Mota ◽  
Daniel J. Pagano ◽  
Marina Enricone Stasiak
Keyword(s):  
Two Phase Flow ◽  
Volume Fraction ◽  
Water Volume ◽  
Phase Flow ◽  
Electrical Capacitance ◽  
Two Phase ◽  
Water Volume Fraction

scholarly journals Modeling of Two-Phase Flow in Rough-Walled Fracture Using Level Set Method

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yunfeng Dai ◽  
Zhifang Zhou ◽  
Jin Lin ◽  
Jiangbo Han
Keyword(s):  
Crude Oil ◽  
Level Set Method ◽  
Level Set ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Contact Angles ◽  
Immiscible Fluids ◽  
Water Volume ◽  
Phase Flow ◽  
Two Phase

To describe accurately the flow characteristic of fracture scale displacements of immiscible fluids, an incompressible two-phase (crude oil and water) flow model incorporating interfacial forces and nonzero contact angles is developed. The roughness of the two-dimensional synthetic rough-walled fractures is controlled with different fractal dimension parameters. Described by the Navier–Stokes equations, the moving interface between crude oil and water is tracked using level set method. The method accounts for differences in densities and viscosities of crude oil and water and includes the effect of interfacial force. The wettability of the rough fracture wall is taken into account by defining the contact angle and slip length. The curve of the invasion pressure-water volume fraction is generated by modeling two-phase flow during a sudden drainage. The volume fraction of water restricted in the rough-walled fracture is calculated by integrating the water volume and dividing by the total cavity volume of the fracture while the two-phase flow is quasistatic. The effect of invasion pressure of crude oil, roughness of fracture wall, and wettability of the wall on two-phase flow in rough-walled fracture is evaluated.

Unsteady Two-Phase Flow Analysis on Water Retarder Performance Using Sliding Mesh Technique and VOF Method

2015 ◽  
Author(s):  
Wonju Lee ◽  
Nahmkeon Hur
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Volume Ratio ◽  
Working Fluid ◽  
Water Volume ◽  
Phase Flow ◽  
Two Phase ◽  
Sliding Mesh ◽  
Mesh Technique

Hydraulic retarders are used as auxiliary brake system in heavy vehicles and high speed trains. A hydraulic retarder is composed of two parts, a rotor and a stator. When the system is activated, the working fluid is injected into the wheel and circulates between the rotor and stator vanes using the resisting torque of the stator to slow down the vehicle. The purpose of this research is to investigate a water retarder system and the details of flow characteristics of the water, and to investigate the device performance as well. The water retarder is basically composed of a rotor and a stator. In the present research, the rotor rotating speed is fixed at 2000 rpm. Since the performance characteristic of the water retarder is dependent upon the water volume ratio, different volume ratios have been investigated. In this paper water retarder simulations are carried out using CFD using sliding mesh technique. To capture the unsteady effects, the cases have been solved as transient simulations using standard k-ε turbulence model. The simulations have been solved as two phase flow, water and air. The results are compared for different water volume ratios. The result show that the air particles are accumulated in the center of the wheels forming a tube shape (doughnut shape) and water particles are at the outside, wrapping the air particles. In addition, torque values are sensitively dependent upon water volume fraction.

Void fraction measurement of the air-water two-phase flow in the sub-channel of a rod bundle geometry based on an impedance meter

2018 ◽  
Vol 115 ◽  
pp. 480-486 ◽  
Author(s):  
Bin Yu ◽  
Wenxiong Zhou ◽  
Liangming Pan ◽  
Hang Liu ◽  
Quanyao Ren ◽  
...  
Keyword(s):  
Void Fraction ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Rod Bundle ◽  
Fraction Measurement ◽  
Impedance Meter

Eulerian Two-Phase Flow Modeling of Steam Direct Contact Condensation for the Fukushima Accident Investigation

2014 ◽  
Author(s):  
Marco Pellegrini ◽  
Giulia Agostinelli ◽  
Hidetoshi Okada ◽  
Masanori Naitoh
Keyword(s):  
Two Phase Flow ◽  
Volume Fraction ◽  
Fluid Model ◽  
Fluid Dynamic ◽  
Interfacial Region ◽  
Phase Flow ◽  
Two Phase ◽  
Fukushima Accident ◽  
Average Cell Size ◽  
Average Cell

Steam condensation is characterized by a relatively large interfacial region between gas and liquid which, in computational fluid dynamic (CFD) analyses, allows the creation of a discretized domain whose average cell size is larger than the interface itself. For this reason generally one fluid model with interface tracking (e.g. volume of fluid method, VOF) is employed for its solution in CFD, since the solution of the interface requires a reasonable amount of cells, reducing the modeling efforts. However, for some particular condensation applications, requiring the computation of long transients or the steam ejected through a large number of holes, one-fluid model becomes computationally too expensive for providing engineering information, and a two-fluid model (i.e. Eulerian two-phase flow) is preferable. Eulerian two-phase flow requires the introduction of closure terms representing the interactions between the two fluids in particular, in the condensation case, drag and heat transfer. Both terms involve the description of the interaction area whose definition is different from the typical one adopted in the boiling analyses. In the present work a simple but effective formulation for the interaction area is given based on the volume fraction gradient and then applied to a validation test case of steam bubbling in various subcooling conditions. It has been shown that this method gives realistic values of bubble detachment time, bubble penetration for the cases of interest in the nuclear application and in the particular application to the Fukushima Daiichi accident.

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