A suitability analysis of transient one-dimensional two-fluid numerical models for simulating two-phase gas-liquid flows based on benchmark problems

2021 ◽  
pp. 105070
Author(s):  
Carina Nogueira Sondermann ◽  
Raphael Viggiano Neves de Freitas ◽  
Felipe Bastos de Freitas Rachid ◽  
Gustavo C.R. Bodstein
Author(s):  
Youn-Gyu Jung ◽  
Moon-Sun Chung ◽  
Sung-Jae Yi

This study discusses on the implementation of an upwind method for a one-dimensional two-fluid model including the surface tension effect in the momentum equations. This model consists of a complete set of six equations including two-mass, two-momentum, and two-internal energy conservation equations having all real eigenvalues. Based on this equation system with upwind numerical method, the present authors first make a pilot code and then solve some benchmark problems to verify whether this model and numerical method is able to properly solve some fundamental one-dimensional two-phase flow problems or not.


Author(s):  
David Heinze ◽  
Thomas Schulenberg ◽  
Lars Behnke

A simulation model for the direct contact condensation of steam in subcooled water is presented that allows determination of major parameters of the process, such as the jet penetration length. Entrainment of water by the steam jet is modeled based on the Kelvin–Helmholtz and Rayleigh–Taylor instability theories. Primary atomization due to acceleration of interfacial waves and secondary atomization due to aerodynamic forces account for the initial size of entrained droplets. The resulting steam-water two-phase flow is simulated based on a one-dimensional two-fluid model. An interfacial area transport equation is used to track changes of the interfacial area density due to droplet entrainment and steam condensation. Interfacial heat and mass transfer rates during condensation are calculated using the two-resistance model. The resulting two-phase flow equations constitute a system of ordinary differential equations, which is solved by means of the explicit Runge–Kutta–Fehlberg algorithm. The simulation results are in good qualitative agreement with published experimental data over a wide range of pool temperatures and mass flow rates.


Author(s):  
Aurelia Chenu ◽  
Konstantin Mikityuk ◽  
Rakesh Chawla

In the framework of PSI’s FAST code system, the TRACE thermal-hydraulics code is being extended for representation of sodium two-phase flow. As the currently available version (v.5) is limited to the simulation of only single-phase sodium flow, its applicability range is not enough to study the behavior of a Sodium-cooled Fast Reactor (SFR) during a transient in which boiling is anticipated. The work reported here concerns the extension of the two-fluid models, which are available in TRACE for steam-water, to sodium two-phase flow simulation. The conventional correlations for ordinary gas-liquid flows are used as basis, with optional correlations specific to liquid metal when necessary. A number of new models for representation of the constitutive equations specific to sodium, with a particular emphasis on the interfacial transfer mechanisms, have been implemented and compared with the original closure models. As a first application, the extended TRACE code has been used to model experiments that simulate a loss-of-flow (LOF) accident in a SFR. The comparison of the computed results, with both the experimental data and SIMMER-III code predictions, has enabled validation of the capability of the modified TRACE code to predict sodium boiling onset, flow regimes, dryout, flow reversal, etc. The performed study is a first-of-a-kind application of the TRACE code to two-phase sodium flow. Other integral experiments are planned to be simulated to further develop and validate the two-phase sodium flow methodology.


2003 ◽  
Vol 125 (2) ◽  
pp. 387-389 ◽  
Author(s):  
Jin Ho Song

A linear stability analysis is performed for a two-phase flow in a channel to demonstrate the feasibility of using momentum flux parameters to improve the one-dimensional two-fluid model. It is shown that the proposed model is stable within a practical range of pressure and void fraction for a bubbly and a slug flow.


1982 ◽  
Vol 104 (3) ◽  
pp. 297-303 ◽  
Author(s):  
C. T. Crowe

The rapidly increasing capability of computers has led to the development of numerical models for gaseous flows and, in turn, gas-particle and gas-droplet flows. This paper reviews the essential features of gas-particle flows from the point of view of model development. Various models that have appeared for one-dimensional and two-dimensional flows are discussed. The advantages and disadvantages of the trajectory and two-fluid models are noted.


Author(s):  
Thomas Beuthe

This paper summarizes the current water hammer simulation capabilities of the CATHENA one-dimensional two-fluid network thermalhydraulics simulation code. The single-phase and one- and two-component two-phase capabilities for simulating void collapse water hammer and water hammer in the presence of noncondensables is discussed. Recent successful efforts to resolve nodalization-dependence observed in the simulation of condensation-induced water hammer are presented along with efforts to develop condensation relationships for simulating condensation-induced water hammer. A summary of current code coupling capabilities is also presented. Possible future efforts to simulate water hammer at supercritical pressures as well as the coupling of CATHENA to piping stress codes are discussed.


1997 ◽  
Vol 63 (611) ◽  
pp. 2377-2385
Author(s):  
Kiyoshi MINEMURA ◽  
Tomomi UCHIYAMA ◽  
Katsuhiko KINOSHITA ◽  
Lin LYU ◽  
Shinji SYODA ◽  
...  

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