scholarly journals A Numerical Study of the Flow and Sediment Interaction in the Middle Reach of the Huai River

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2041
Author(s):  
Jin Ni ◽  
Bangyi Yu ◽  
Peng Wu
Keyword(s):  
Numerical Study ◽  
Flow Direction ◽  
River Channel ◽  
Continuous Series ◽  
Middle Reach ◽  
Erosion And Deposition ◽  
Huai River ◽  
Variation Rate ◽  
The Relationship ◽  
Present Simulation

In recent years, the incoming sediments from upstream of the Huai River have continuously decreased. The relationship between flow and sediment has significantly changed. Therefore, the erosion and deposition characteristics of the river could be affected. To investigate this interaction between flow and sediment, the present study was conducted using the Wanglin section in the middle reach of the Huai River as the study site. A 1D hydrodynamic model was developed and validated using field data. Data from 1985–2014 were used as a continuous series while data from 2004–2014 were used as a repetitive series. The sediment variation and distribution processes at different locations were discussed. It was found that the river channel displayed several notable characteristics. In the flow direction, the channel had frontal erosion and backward deposition. The variation rate was relatively slow. With reduced sediment, the overall deposition at the Wanglin section was significantly mitigated. Future recommendations are provided based on the present simulation for flood mitigation along the Huai River.

scholarly journals Numerical Simulation on the Boiling Flow Patterns of Al2O3-Water Nanofluid in Micro/Minichannel under Different Hypergravity Levels and Directions

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Gen Li ◽  
Xiande Fang
Keyword(s):  
Vapor Phase ◽  
Thermophysical Properties ◽  
Numerical Study ◽  
Flow Direction ◽  
Flow Patterns ◽  
Wall Function ◽  
Grid Structure ◽  
Phase Transform ◽  
Boiling Flow ◽  
Present Simulation

Due to the influence of hypergravity that has a significant impact on the performance of heat exchanger in aircraft, which is crucial for electronic equipment on the plane and life safeties of pilots and passengers, a numerical study is conducted using Fluent 20R2 software to investigate boiling flow patterns under different gravity levels and directions. In this study, the thermophysical properties of nanofluids are analyzed, and select the most suitable theoretical model of thermal conductivity, viscosity, and surface tension for present simulations. Choose the grid structure of 122,116 after independence check for grid. The VOF approach is employed for present simulation, and the standard κ − ε turbulence model with nonequilibrium wall function is used. The UDFs for mass and energy source terms and thermophysical properties of nanofluid are developed for calculating the HTC of nanofluid. There are three different gravity directions with gravity levels from 1 g to 9 g. The results show that the flow pattern becomes the stratified flow with the gravity levels increasing when the hypergravity direction is perpendicular to the flow direction, and the HTCs decrease with the increment of gravity levels. The vapor-phase transform to circular when the hypergravity direction is the same as the flow direction, and the HTCs of the second half of the tube are decreasing with the increasing gravity levels. On the contrary, the vapor phase is elongated when the hypergravity direction is opposite to the flow direction, and the HTCs show the enhanced tendency.

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

scholarly journals Generation of Reverse Meniscus Flow by Applying An Electromagnetic Brake

2021 ◽  
Author(s):  
Alexander Vakhrushev ◽  
Abdellah Kharicha ◽  
Ebrahim Karimi-Sibaki ◽  
Menghuai Wu ◽  
Andreas Ludwig ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Lorentz Force ◽  
Applied Magnetic Field ◽  
Numerical Study ◽  
Flow Direction ◽  
Experimental Studies ◽  
Submerged Entry Nozzle ◽  
Mean Flow ◽  
Slab Caster ◽  
The Mean

AbstractA numerical study is presented that deals with the flow in the mold of a continuous slab caster under the influence of a DC magnetic field (electromagnetic brakes (EMBrs)). The arrangement and geometry investigated here is based on a series of previous experimental studies carried out at the mini-LIMMCAST facility at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). The magnetic field models a ruler-type EMBr and is installed in the region of the ports of the submerged entry nozzle (SEN). The current article considers magnet field strengths up to 441 mT, corresponding to a Hartmann number of about 600, and takes the electrical conductivity of the solidified shell into account. The numerical model of the turbulent flow under the applied magnetic field is implemented using the open-source CFD package OpenFOAM®. Our numerical results reveal that a growing magnitude of the applied magnetic field may cause a reversal of the flow direction at the meniscus surface, which is related the formation of a “multiroll” flow pattern in the mold. This phenomenon can be explained as a classical magnetohydrodynamics (MHD) effect: (1) the closure of the induced electric current results not primarily in a braking Lorentz force inside the jet but in an acceleration in regions of previously weak velocities, which initiates the formation of an opposite vortex (OV) close to the mean jet; (2) this vortex develops in size at the expense of the main vortex until it reaches the meniscus surface, where it becomes clearly visible. We also show that an acceleration of the meniscus flow must be expected when the applied magnetic field is smaller than a critical value. This acceleration is due to the transfer of kinetic energy from smaller turbulent structures into the mean flow. A further increase in the EMBr intensity leads to the expected damping of the mean flow and, consequently, to a reduction in the size of the upper roll. These investigations show that the Lorentz force cannot be reduced to a simple damping effect; depending on the field strength, its action is found to be topologically complex.

Fluvial geomorphology of the Middle Reach of the Huai River

2014 ◽  
Vol 29 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Bang-yi YU ◽  
Peng WU ◽  
Jue-yi SUI ◽  
Xing-ju YANG ◽  
Jin NI
Keyword(s):  
Fluvial Geomorphology ◽  
Middle Reach ◽  
Huai River

The impact of organizational position level and cultural flow direction on the relationship between cultural intelligence and expatriate cross-border adaptation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ying Zhang ◽  
Yuran Li ◽  
Mark Frost ◽  
Shiyu Rong ◽  
Rong Jiang ◽  
...  
Keyword(s):  
Cultural Intelligence ◽  
Flow Direction ◽  
Power Distance ◽  
Cultural Adjustment ◽  
Data Set ◽  
Content Type ◽  
Cross Border ◽  
Organizational Position ◽  
The Impact ◽  
The Relationship

PurposeThis paper aims to examine the critical role played by cultural flow in fostering successful expatriate cross-border transitions.Design/methodology/approachThe authors develop and test a model on the interplay among cultural intelligence, organizational position level, cultural flow direction and expatriate adaptation, using a data set of 387 expatriate on cross-border transitions along the Belt & Road area.FindingsThe authors find that both organizational position level and cultural flow moderate the relationship between cultural intelligence and expatriate adaptation, whereby the relationship is contingent on the interaction of organizational position status and assignment directions between high power distance and low power distance host environments.Originality/valuePrevious research has shown that higher levels of cultural intelligence are positively related to better expatriate adaptation. However, there is a lack of research on the effect of position difference and cultural flow on such relationship. Our study is among the first to examine how the interaction between cultural flow and organizational position level influences the cultural intelligence (CI) and cultural adjustment relationship in cross-cultural transitions.

Failure behavior analysis of steel strip–reinforced flexible pipe under combined tension and internal pressure

2018 ◽  
Vol 33 (6) ◽  
pp. 727-753
Author(s):  
Wei Chen ◽  
Haichao Xiong ◽  
Yong Bai
Keyword(s):  
Internal Pressure ◽  
Numerical Study ◽  
Steel Strip ◽  
Sensitivity Study ◽  
Failure Behavior ◽  
Load Path ◽  
Flexible Pipe ◽  
Fe Method ◽  
Axial Extension ◽  
The Relationship

The mechanical behaviors of steel strip–reinforced flexible pipe (steel strip PSP) under combined axial extension → internal pressure ( T→ P) load path were investigated. Typical failure characteristics of pipe samples under pure internal pressure and T→ P load path were identified in the full-scale experiments. A theoretical model for pipe under tension load was proposed to capture the relationship between axial extension of the pipe body and stress state of the steel strip. Numerical study based on finite element (FE) method was conducted to simulate the experiment process, and good agreement between FE data and experiment results were observed. Sensitivity study was conducted to study the effect of some key parameters on the pipe antiburst capacities in T→P load path; the effect of preloaded internal pressure on the pipe tensile capacity in P→T load path was also studied. Useful conclusions were drawn for the design and application of the steel strip PSP.

scholarly journals Numerical Study of Hydrodynamic Impact on Bubbly Water

2015 ◽  
Author(s):  
Mehdi Elhimer ◽  
Aboulghit El Malki Alaoui ◽  
Kilian Croci ◽  
Céline Gabillet ◽  
Nicolas Jacques
Keyword(s):  
Volume Fraction ◽  
Numerical Study ◽  
Numerical Data ◽  
Void Volume Fraction ◽  
Bubbly Liquid ◽  
Impact Loads ◽  
Hydrodynamic Impact ◽  
Physical Mechanisms ◽  
The Impact ◽  
The Relationship

The phenomenon of slamming on a bubbly liquid has many occurrences in marine and costal engineering. However, experimental or numerical data on the effect of the presence of gas bubbles within the liquid on the impact loads are scarce and the related physical mechanisms are poorly understood. The aim of the present paper is to study numerically the relationship between the void volume fraction and the impact loads. For that purpose, numerical simulations of the impact of a cone on bubbly water have been performed using the finite element code ABAQUS/Explicit. The present results show the diminution of the impact loads with the increase of the void fraction. This effect appears to be related to the high compressibility of the liquid-gas mixture.

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