Validation of the Moody and Henry–Fauske Critical Flow Models in apros Against Marviken Critical Flow Experiments

2020 ◽  
Vol 6 (4) ◽  
Author(s):  
Milan Tesinsky
Keyword(s):  
Process Simulation ◽  
Discharge Coefficient ◽  
Simulation Software ◽  
Critical Flow ◽  
Good Match ◽  
Two Phase Flows ◽  
Two Phase ◽  
Flow Models ◽  
Subcooled Water ◽  
Flow Experiments

Abstract The Moody and Henry–Fauske critical flow models implemented in Advanced Process Simulation Software (apros) have been validated against Marviken critical flow experiments and compared with other available simulations of the same experiments. Both models in combination with discharge coefficient 0.75 (suggested for best estimate calculations) produce results close to the experimental data for two-phase flows, while one-phase flow of subcooled water is underpredicted. Using discharge coefficient 1.0 for subcooled water leads to a good match with the experimental results, while two-phase flows become overpredicted.

A Choking Model With Thermal Non-Equilibrium for Initially Subcooled Water

2018 ◽  
Author(s):  
Lv Yufeng ◽  
Zhao Minfu ◽  
Li Weiqing
Keyword(s):  
Bubbly Flow ◽  
Flow Regimes ◽  
Critical Flow ◽  
Vapor Bubbles ◽  
Two Phase ◽  
Subcooled Water ◽  
Wide Range ◽  
Frictional Forces ◽  
Flow Closure ◽  
Non Equilibrium

Mechanical non-homogeneous and thermal non-equilibrium phenomenon exists in two-phase critical flow compared with single phase flow. A one-dimensional two-fluid critical flow model is developed for initially subcooled water flowing in pipe or orifices. The model accounts for thermal nonequilibrium between the liquid and vapor bubbles and for interphase relative motion. In this model, an improved correlation to calculate flashing inception location and surperheat is proposed. The model consists of six conservation equations as well as a seventh equation representing bubble growth in bubbly flow. Closure of the set of governing equations is performed with constitutive relationships which determine the interfacial momentum terms due to mass exchange, wall to liquid and wall to vapour frictional forces, liquid to gas interfacial force and interfacial heat transfer rate. The model considers the development of three flow regimes, namely, bubbly, churn and annular flow regimes. Model predictions compare favorably with experimental data over a wide range of pressures and pipe diameters and lengths.

Assessment of Two Phase Critical Flow Models and Implementation in Fast Transient Fluid Dynamics Software

2015 ◽  
Author(s):  
Philippe Lafon ◽  
Mohamed Essadki ◽  
Yann Bartosiewicz ◽  
Jean-Marie Seynhaeve
Keyword(s):  
Critical Flow ◽  
Vapor Mixture ◽  
Two Phase ◽  
Subcooled Liquid ◽  
Moby Dick ◽  
Flow Models ◽  
High Temperature And Pressure ◽  
Temperature And Pressure ◽  
Fast Transient ◽  
Dem Model

The discharge of a subcooled liquid or a liquid-vapor mixture at high temperature and pressure can occur in many industrial situations. This paper is focused on the analysis of critical flow models that are already available in the fast transient dynamics software EUROPLEXUS, or that are being implemented as new break boundary conditions. The results of the Moody, Fauske, Flinta, Henry-Fauske and DEM models are presented and compared with the Super Moby Dick experimental results. The best results are obtained for the DEM. Then preliminary results concerning the implementation of the DEM model as a break boundary condition in EUROPLEXUS are given.

Effects of Liquid Properties on Pressure Drop of Two-Phase Gas-Liquid Flows Through a Microchannel

2003 ◽  
Author(s):  
Akimaro Kawahara ◽  
Michio Sadatomi ◽  
Kazuya Okayama ◽  
Masahiro Kawaji
Keyword(s):  
Pressure Drop ◽  
Friction Factor ◽  
Single Phase ◽  
Phase Flow ◽  
Distilled Water ◽  
Two Phase Flows ◽  
Two Phase ◽  
Factor Data ◽  
Flow Experiments ◽  
Working Liquid

Adiabatic experiments were conducted to measure pressure drop for single-phase liquid and gas-liquid two-phase flows through a circular microchannel with an internal diameter of 100 μm. In order to study the effects of liquid properties on the pressure drop, aqueous solutions of ethanol with different mass concentrations (4.8, 9.5, 49 and 100 wt%) in distilled water and distilled water were used as the working liquid, while nitrogen gas was used for the gas phase. The surface tension of the working liquid ranged from 0.023 N/m (100 wt% ethanol) to 0.072 N/m (water), and viscosity from 0.9 mPa·s (water) to 3.4 mPa·s (49 wt% ethanol aqueous solution). For the single-phase flow experiments, the friction factor data were obtained for each working liquid used, over a Reynolds number range of 2 < Re < 800. For the two-phase flow experiments, pressure drop data were collected over 0.2 < jG < 7 m/s for the superficial gas velocity and 0.1 < jL < 1 m/s for the superficial liquid velocity. For single-phase flows, friction factor data were shown to be in reasonable agreement with conventional theory. Furthermore, early transition from laminar to turbulent flow was not observed over the present experimental flow conditions. For two-phase flows, Lockhart & Martinelli’s correlation was found to be capable of predicting the present pressure drop data irrespective of the working liquid tested, if an appropriate constant needed in the correlation is adopted.

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