Experiments and Numerical Simulations of Water Flow over a Slit Weir for Measuring Very Small Discharges at River Intakes

2021 ◽  
Author(s):  
Daniela-Elena Gogoase Nistoran ◽  
Stefan-Mugur Simionescu ◽  
Nicoleta-Octavia Tanase
Keyword(s):  
Numerical Simulations ◽  
Water Flow

Numerical Simulations on Supercritical Water Flow Instability

2014 ◽  
Author(s):  
Jingjing Li ◽  
Tao Zhou ◽  
Mingqiang Song ◽  
Yanping Huang
Keyword(s):  
Numerical Simulations ◽  
Water Flow ◽  
Mass Flow ◽  
Supercritical Water ◽  
Flow Instability ◽  
Natural Circulation ◽  
Heating Power ◽  
Circulation Loop ◽  
Natural Circulation Loop ◽  
Parallel Channels

3-D simulation of supercritical water flow instability in parallel channels and a natural circulation loop are presented. Results are obtained for various heating powers. The results show that, in the natural circulation loop the steady state mass flow will firstly increase with the heating power and then decrease. And mass flow grows with the growing of the inlet temperature, decreases with the growing of system pressure. Under a large heat flux, the parallel channels will experience the flow instability of out phase mass flow oscillation. And the oscillation amplitude will grow with the growing of heating power. At last, the numerical simulations are validated by B.T. Swapnalee’s experience formula.

scholarly journals CFD Code Validation against Stratified Air-Water Flow Experimental Data

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
F. Terzuoli ◽  
M. C. Galassi ◽  
D. Mazzini ◽  
F. D'Auria
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Water Flow ◽  
Nuclear Reactor ◽  
Cold Water ◽  
Three Dimensional ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Two Phase ◽  
Code Validation

Pressurized thermal shock (PTS) modelling has been identified as one of the most important industrial needs related to nuclear reactor safety. A severe PTS scenario limiting the reactor pressure vessel (RPV) lifetime is the cold water emergency core cooling (ECC) injection into the cold leg during a loss of coolant accident (LOCA). Since it represents a big challenge for numerical simulations, this scenario was selected within the European Platform for Nuclear Reactor Simulations (NURESIM) Integrated Project as a reference two-phase problem for computational fluid dynamics (CFDs) code validation. This paper presents a CFD analysis of a stratified air-water flow experimental investigation performed at the Institut de Mécanique des Fluides de Toulouse in 1985, which shares some common physical features with the ECC injection in PWR cold leg. Numerical simulations have been carried out with two commercial codes (Fluent and Ansys CFX), and a research code (NEPTUNE CFD). The aim of this work, carried out at the University of Pisa within the NURESIM IP, is to validate the free surface flow model implemented in the codes against experimental data, and to perform code-to-code benchmarking. Obtained results suggest the relevance of three-dimensional effects and stress the importance of a suitable interface drag modelling.

Quantifying coupled deformation and water flow in the rhizosphere using X-ray microtomography and numerical simulations

2013 ◽  
Vol 376 (1-2) ◽  
pp. 95-110 ◽  
Author(s):  
Jazmín E. Aravena ◽  
Markus Berli ◽  
Siul Ruiz ◽  
Francisco Suárez ◽  
Teamrat A. Ghezzehei ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Water Flow ◽  
X Ray

scholarly journals Influence of Erodible Beds on Shallow Water Hydrodynamics during Flood Events

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3340
Author(s):  
David Santillán ◽  
Luis Cueto-Felgueroso ◽  
Alvaro Sordo-Ward ◽  
Luis Garrote
Keyword(s):  
Numerical Simulations ◽  
Shallow Water ◽  
Water Flow ◽  
Water Depth ◽  
Velocity Fields ◽  
Economic Losses ◽  
Flood Events ◽  
Erosion And Deposition ◽  
The Impact ◽  
Erodible Beds

Flooding has become the most common environmental hazard, causing casualties and severe economic losses. Mathematical models are a useful tool for flood control, and current computational resources let us simulate flood events with two-dimensional (2D) approaches. An open question is whether bed erosion must be accounted for when it comes to simulating flood events. In this paper we answer this question through numerical simulations using the 2D depth-averaged shallow-water equations. We analyze the effect of mobile beds on the flow patterns during flood events. We focus on channel confluences where water flow and sediment mobilization have a marked 2D behavior. We validate our numerical simulations with laboratory experiments of erodible beds with satisfactory results. Moreover, our sensitivity analysis indicates that the bed roughness model has a great influence on the simulated erosion and deposition patterns. We simulate the sediment transport and its influence on the water flow in a real river confluence during flood events. Our simulations show that the erosion and deposition processes play an important role on the water depth and flow velocity patterns. Accounting for the mobile bed leads to smoother water depth and velocity fields, as abrupt fields for the non-erodible model emerge from the irregular bed topography. Our study highlights the importance of accounting for erosion in the simulation of flood events, and the impact on the water depth and velocity fields.

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