B207 Measurement of Reynolds Stress of Gas-Liquid Two-Phase Bubbly Flow in a Vertical Pipe

2001 ◽  
Vol 2001 (0) ◽  
pp. 393-394
Author(s):  
Yuichi KONDO ◽  
Sigeo HOSOKAWA ◽  
Rentarou KANZAWA ◽  
Akio TOMIYAMA
Keyword(s):  
Reynolds Stress ◽  
Bubbly Flow ◽  
Vertical Pipe ◽  
Two Phase

scholarly journals KARAKTERISITIK FLOW PATERN PADA ALIRAN DUA FASE GAS-CAIRAN MELEWATI PIPA VERTIKAL

2012 ◽  
Vol 11 (2) ◽  
pp. 117
Author(s):  
PRIYO HERU ADIWIBOWO
Keyword(s):  
Flow Pattern ◽  
Power Plants ◽  
Bubbly Flow ◽  
Digital Camera ◽  
Vertical Pipe ◽  
Two Phase ◽  
Pressurized Water ◽  
Industrial Facilities ◽  
Multi Phase ◽  
Pattern Visualization

Multi-phase flows are widely encountered in several engineering and industrial facilities, such as conventional steam power  plants, evaporators and condensers, pressurized-water nuclear reactors, a wide variety of petroleum industries, chemicals and  food processing industries. Surely, in the complex pipeline  installation of these systems, vertical pipe will be commonly  used for pipe connection. The purpose of this work is to investigate the flow pattern of gas-liquid two phase in the vertical pipe. Experiments will be performed in a 36 mm ID  acrylic pipe vertical. Superifical liquid velocities and volumetric gas quality will be varied 0.3~1,1 m/s and 0.05~0.2 respectively. Digital camera will be used for flow pattern  visualization in the vertical pipe. It was observed that effect of vertical pipe on flow pattern formed cluster bubbly flow for low volumetric gas quality with high superifical liquid velocities. For  superifical liquid velocities with medium volumetric gas quality formed homogeneous bubbly flow and high volumetric gas quality is dense bubbly flow.

scholarly journals Ultrasonic Measurement for the Experimental Investigation of Velocity Distribution in Vapor-Liquid Boiling Bubbly Flow

2021 ◽  
Vol 12 (1) ◽  
pp. 16-28
Author(s):  
Wongsakorn Wongsaroj ◽  
Hideharu Takahashi ◽  
Natee Thong-Un ◽  
Hiroshige Kikura
Keyword(s):  
Velocity Distribution ◽  
Pipe Flow ◽  
Pipe Wall ◽  
Bubbly Flow ◽  
Ultrasonic Measurement ◽  
Subcooled Boiling ◽  
Vertical Pipe ◽  
Two Phase ◽  
Flow Apparatus ◽  
Vapor Liquid

This study proposes an ultrasonic velocity profiler (UVP) with a single ultrasonic gas-liquid two-phase separation (SUTS) technique to measure the velocity distribution of vapor-liquid boiling bubbly flow. The proposed technique is capable of measuring the velocity of the vapor bubble and liquid separately in boiling conditions. To confirm the viability of the measurement technique, the experiment is conducted on vertical pipe flow apparatus. The ultrasonic transmission and effect of ultrasonic refraction through the pipe wall and water are investigated at ambient temperature until subcooled boiling temperature is reached. The velocity profile in the water at elevated temperature is measured to verify the ability of the technique in this application. The bubbly flow velocity distribution measurement in boiling conditions is then demonstrated. The results show that the proposed technique can effectively investigate the velocity of both phases under various fluid conditions in boiling bubbly flow.

Influence of Bubbles on the Turbulence Anisotropy

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Igor A. Bolotnov
Keyword(s):  
Fluid Dynamics ◽  
Reynolds Stress ◽  
Bubbly Flow ◽  
Bubbly Flows ◽  
Cfd Modeling ◽  
Two Phase ◽  
Cfd Models ◽  
Turbulence Anisotropy ◽  
Multiphase Fluid ◽  
Turbulent Models

Direct numerical simulation (DNS) with interface tracking of turbulent bubbly flows is becoming a major tool in advancing our knowledge in the area of multiphase modeling research. A comprehensive analysis of the turbulent flow structure allows us to evaluate the state-of-the-art computational multiphase fluid dynamics (CMFD) models and to propose new closure laws. The presented research will demonstrate how the multiphase DNS data can inform the development of computational fluid dynamics (CFD) models. In particular, the Reynolds stress distribution will be evaluated for single- and two-phase bubbly flows and the level of turbulence anisotropy will be measured in several scenarios. The results will help determine if the isotropic turbulent models are suitable for bubbly flow applications or if there is a strong need to apply and develop Reynolds-stress turbulent models for two-phase flow CFD modeling.

Influence of Bubbles on the Turbulence Anisotropy

2012 ◽  
Author(s):  
Igor A. Bolotnov
Keyword(s):  
Fluid Dynamics ◽  
Reynolds Stress ◽  
Bubbly Flow ◽  
Research Area ◽  
Bubbly Flows ◽  
Cfd Modeling ◽  
Two Phase ◽  
Cfd Models ◽  
Turbulence Anisotropy ◽  
Turbulent Models

Direct numerical simulations (DNS) with interface tracking of turbulent bubbly flows are becoming a major tool in advancing our knowledge in the multiphase modeling research area. Comprehensive analysis of turbulent flow structure allows to evaluate the state-of-the-art computational multiphase fluid dynamics (CMFD) models and to propose new closure laws. The presented research will demonstrate how the multiphase DNS data can inform the development of computational fluid dynamics (CFD) models. In particular, Reynolds stress distribution will be evaluated for single and two-phase bubbly flows and the level of turbulence anisotropy will be measured in several scenarios. The results will help determine if the isotropic turbulent models are suitable for bubbly flow applications or there is a strong need to apply and develop Reynolds-stress turbulent models for two-phase flow CFD modeling.

scholarly journals Radial Distribution of Volume Fraction of Gas Phase in Gas-Liquid Two-Phase Bubbly Flow in a Vertical Pipe.

1996 ◽  
Vol 10 (4) ◽  
pp. 389-396 ◽  
Author(s):  
Tadashi SAKAGUCHI ◽  
Hiroki IJIRI ◽  
Masayuki TABASAKI ◽  
Hideaki SHAKUTSUI
Keyword(s):  
Gas Phase ◽  
Radial Distribution ◽  
Volume Fraction ◽  
Bubbly Flow ◽  
Vertical Pipe ◽  
Two Phase

2D Velocity Vector Profile Measurement and Phase Separation on Swirling Bubbly Flow Using Ultrasound Technique

2019 ◽  
Author(s):  
Wongsakorn Wongsaroj ◽  
Hideharu Takahashi ◽  
Hiroshige Kikura ◽  
Natee Thong-un
Keyword(s):  
Velocity Distribution ◽  
Velocity Vector ◽  
Nuclear Reactor ◽  
Bubbly Flow ◽  
Profile Measurement ◽  
Vertical Pipe ◽  
Two Phase ◽  
Ultrasound Technique ◽  
Image Velocimetry ◽  
Flow Apparatus

Abstract Two-phase swirling bubbly flow is a complex phenomenon which occurs in several industries such as a nuclear reactor. Its characteristic is indispensably necessary to be investigated especially the multi-dimensional velocity distribution. This present paper describes the development of Ultrasonic Velocity Profiler (UVP) method which is a noninvasive measurement and needless of optical access, to obtain a two dimensional (2D) velocity distribution of the bubble and liquid phase in swirling bubbly flow simultaneously. The measurement result is represented in the form of the 2D velocity vector. To achieve the target, the multiple transducers and developed signal processing have been applied to the UVP system to measure a 2D velocity vector affected by bubble and liquid separately. For confirming the ability of Developed-UVP, the experiment was conducted on a vertical pipe co-current flow apparatus. The UVP measurement was demonstrated non-intrusively and without the optical requirement. The measurement applicability of Developed-UVP was evaluated by comparing with Particle Image Velocimetry (PIV) method on liquid flow and bubbly flow. Then, it was applied to obtain the 2D velocity vector in swirling bubbly flow. The velocity vector of the bubble and liquid could be separated clearly. Also, velocity distribution in swirling motion which was interacted of both phases was investigated understandably by using this measurement technique.

Measurements of single-phase and two-phase flows in a vertical pipe using ultrasonic pulse Doppler method and ultrasonic time-domain cross-correlation method

2013 ◽  
Vol 35 (3) ◽  
Author(s):  
Tat Thang Nguyen ◽  
Hiroshige Kikura ◽  
Ngoc Hai Duong ◽  
Hideki Murakawa ◽  
Nobuyoshi Tsuzuki
Keyword(s):  
Time Domain ◽  
Cross Correlation ◽  
Single Phase ◽  
Ultrasonic Pulse ◽  
Phase Flow ◽  
Beam Diameter ◽  
Vertical Pipe ◽  
Two Phase ◽  
Ultrasonic Time ◽  
Pulse Doppler

Ultrasonic Velocity Profile (UVP) method for measurement of single-phase and two-phase flow in a vertical pipe has recently been developed in the Laboratory for industrial and Environmental Fluid Dynamics, Institute of Mechanics, VAST. The signal processings of the UVP method include the ultrasonic pulse Doppler method (UDM)and the ultrasonic time-domain cross-correlation (UTDC) method. For two-phase flow, simultaneous measurements of both liquid and gas are enabled by using a multi-wave ultrasonic transducer (multi-wave TDX). The multi-wave TDX is able to emit and receive ultrasound of two different center frequencies of 2 MHz and 8 MHz at the same time and position. 2 MHz frequency with beam diameter 10 mm is exploited for measurement of gas. 8 MHz one with beam diameter 3 mm is used for liquid. Measurements have been carried out for laminar and turbulent single-phase flows and bubbly counter-current two-phase flows in two flow loops using two vertical pipes of 26 mm inner diameter (I.D.) and 50 mm I.D. respectively. Based on the measured results, assessment of each method is clarified. Applicability of each method for different conditions of pipe flow has been tested. Suggestions for application of the two methods have been recommended.

Theoretical Post-Dryout Heat Transfer Model

2018 ◽  
Vol 1 (1) ◽  
pp. 142-150
Author(s):  
Murat Tunc ◽  
Ayse Nur Esen ◽  
Doruk Sen ◽  
Ahmet Karakas
Keyword(s):  
Heat Transfer ◽  
Droplet Diameter ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Operating Pressure ◽  
Vertical Pipe ◽  
Two Phase ◽  
Experimental Values ◽  
Reactor Operating ◽  
Coolant System

A theoretical post-dryout heat transfer model is developed for two-phase dispersed flow, one-dimensional vertical pipe in a post-CHF regime. Because of the presence of average droplet diameter lower bound in a two-phase sparse flow. Droplet diameter is also calculated. Obtained results are compared with experimental values. Experimental data is used two-phase flow steam-water in VVER-1200, reactor coolant system, reactor operating pressure is 16.2 MPa. On heater rod surface, dryout was detected as a result of jumping increase of the heater rod surface temperature. Results obtained display lower droplet dimensions than the experimentally obtained values.

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