A transient analysis of slug flow in a horizontal pipe using Slug Tracking model: void and pressure wave

Author(s):  
Jéssica Leonel Gonçalves ◽  
Ricardo Augusto Mazza
Author(s):  
Bruna Patricia Naidek ◽  
Kaique Leite ◽  
Camilla Verbiski Andrade ◽  
Cristiane Cozin ◽  
Fausto Arinos Barbuto ◽  
...  
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Author(s):  
Afshin Goharzadeh ◽  
Peter Rodgers

This paper presents an experimental study of gas-liquid slug flow inside a horizontal pipe. The influence of air bubble passage on liquid flow is characterized using Particle Image Velocimetry (PIV) combined with Refractive Index Matching (RIM) and fluorescent tracers. A physical insight into the velocity distribution within slug flow is presented. It was observed that the slug flow significantly influences the velocity profile in the liquid film. Measured velocity distributions also revealed a significant drop in the velocity magnitude immediately upstream of the slug nose. These findings aim to aid an understanding of the mechanism of solid transportation in slug flows.


Author(s):  
Qian Sun ◽  
Tianji Peng ◽  
Zhiwei Zhou ◽  
Zhibin Chen ◽  
Jieqiong Jiang

Dual-functional Lithium Lead Test Blanket Module (DFLL-TBM) was proposed by China for testing in the International Thermonuclear Experimental Reactor (ITER).When an in-TBM helium coolant tube breaks, high pressure helium will discharge into the Pb-Li breeding zones. The pressure shock in the TBM will threaten the structural integrity and safety of ITER. Simulation and analysis on helium coolant tube break accident of DFLL-TBM was performed, and two cases with different break sizes were considered. Computational results indicate that intense pressure waves spread quickly from the break to the surrounding structures and the variation of pressure in the TBM breeding box is drastic especially when the pressure wave propagation encounters large resistance such as at the bending corner of the flow channel, the inlet and outlet of Pb-Li, etc. The maximum pressure in the TBM breeding box which is even higher than the operating pressure of helium also occurs in these zones. Although the pressure shock lasts for a very short time, its effect on the structural integrity of DFLL-TBM needs to be paid attention to.


Author(s):  
J. N. E. Carneiro ◽  
R. Fonseca Jr. ◽  
A. J. Ortega ◽  
R. C. Chucuya ◽  
A. O. Nieckele ◽  
...  

Author(s):  
Marek Czapp ◽  
Matthias Utschick ◽  
Johannes Rutzmoser ◽  
Thomas Sattelmayer

Investigations on gas-liquid flows in horizontal pipes are of immanent importance for Reactor Safety Research. In case of a breakage of the main cooling circuit of a Pressurized Water Reactor (PWR), the pressure losses of the gas-liquid flow significantly govern the loss of coolant rate. The flow regime is largely determined by liquid and gas superficial velocities and contains slug flow that causes high-pressure pulsations to the infrastructure of the main cooling circuit. Experimental and numerical investigations on adiabatic slug flow of a water-air system were carried out in a horizontal pipe of about 10 m length and 54 mm diameter at atmospheric pressure and room temperature. Stereoscopic high-speed Particle Image Velocimetry in combination with Laser Induced Fluorescence was successfully applied on round pipe geometry to determine instantaneous three-dimensional water velocity fields of slug flows. After grid independence studies, numerical simulations were run with the open-source CFD program OpenFOAM. The solver uses the VOF method (Volume of Fluid) with phase-fraction interface capturing approach based on interface compression. It provides mesh refinement at the interfacial area to improve resolution of the interface between the two phases. Furthermore, standard k-ε turbulence model was applied in an unsteady Reynolds averaged Navier Stokes (URANS) model to resolve self-induced slug formation. The aim of this work is to present the feasibility of both relatively novel possibilities of determining two-phase slug flows in pipes. Experimental and numerical results allow the comparison of the slug initiation and expansion process with respect to their axial velocities and cross-sectional void fractions.


2018 ◽  
Author(s):  
Okto Dinaryanto ◽  
Arif Widyatama ◽  
Maya Prestinawati ◽  
Indarto ◽  
Deendarlianto
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2019 ◽  
Vol 178 ◽  
pp. 1-13 ◽  
Author(s):  
P. Babakhani Dehkordi ◽  
L.P.M. Colombo ◽  
E. Mohammadian ◽  
D. Arnone ◽  
A. Azdarpour ◽  
...  

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