3-D Granular Simulation on the Process of Slope Failure and Collapse

2011 ◽  
Vol 378-379 ◽  
pp. 489-492 ◽  
Author(s):  
Bing Yang ◽  
Jun Yang
Keyword(s):  
Slope Failure ◽  
Flow Model ◽  
Failure Process ◽  
Three Dimensional ◽  
Great Influence ◽  
Seismic Load ◽  
Different Shapes ◽  
Property Losses ◽  
Granular Simulation ◽  
Landslide Movement

Landslides induced by many reasons had resulted in heavy casualties and property losses. Therefore, the research on the failure process of the slope and its final accumulation state is necessary. In this paper, three-dimensional particle flow model is established in PFC3D to simulate the slope failure process, triggered by gravity and seismic load respectively, and the final accumulation state. The landslide movement passing valleys of different shapes are studied and compared. The results show that the shape of valley section has great influence for both load cases.

A Three Dimensional Simulation of M-ICAR Process

2012 ◽  
Vol 516-517 ◽  
pp. 54-57
Author(s):  
Quan Yue Geng ◽  
Jie Wang ◽  
Hong Wei Zhang ◽  
Hui Jia
Keyword(s):  
Water Level ◽  
Flow Model ◽  
Hydraulic Retention Time ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Great Influence ◽  
Mixture Flow ◽  
Phase Volume Fraction ◽  
Dimensional Simulation ◽  
Settling Process

Adopting standard k-ε turbulent model and mixture flow model, settling process and decant process was simulated using 3-d numerical simulation in M-ICAR(Mixture-Intermittently Cycle Aeration Reactor) process to analyze the changes of sludge phase volume fraction. The simulation results showed that the changes of feeding wastewater had great influence on sludge settle ability in decant process, and the position of decanter needed optimized; it had no influence on sludge settle ability in settling process. For considering the lowest hydraulic retention time, the research controlled maximum feeding wastewater for 1610m3/h. Internal recycle had no influence on sludge settle ability. Two methods were proposed: the first one, the water level of decanter was set 3.9m (sludge volume fraction of this suspended area was less than 0.05), feeding velocity was 0.07 m/s; the second, keep the water level of decanter 3.75 m, reduce feeding velocity (preliminary setting feeding velocity 0.06 m/s). The two methods had no influence on sludge settle ability.

Progressive Deformation on Defective Pile Reinforced Slope

2017 ◽  
Vol 873 ◽  
pp. 248-253
Author(s):  
Shi Wei Hou ◽  
Shi He Ma ◽  
Xu Li Liu ◽  
Ying Liu
Keyword(s):  
Plastic Strain ◽  
Slope Failure ◽  
Progressive Failure ◽  
Failure Process ◽  
Three Dimensional ◽  
Equivalent Plastic Strain ◽  
Soil Arching ◽  
Reinforced Slope ◽  
Stress Curve ◽  
The Stability

The slopes reinforced by anti-slide piles were simulated in this paper. The setting position, pile spacing and anchorage depth of integrated piles were discussed with strength reduction method. The results show that the pile position should depart slope into two stages, and the further strain would be limited. When the spacing of the anti-slide piles is 2-3 times of pile diameter, it has a soil arching effect to wedge the soil. The anchorage depth can affect the form of the potential sliding surface. Three kinds of defective piles were studied to research deformation of slope reinforced by defective piles. The defective piles were namely expanded pile, necking pile and segregationpile. The equivalent plastic strain zone was used to judge the slope failure, and then the stability and deformation process of the three-dimensional slope were simulated. By comparing the plastic strain, safety coefficient curve and pile-soil stress curve, between the defective pile and integrated pile, the progressive failure process of the reinforced slope was analyzed, including the formation process of the macroscopic shear zone.

500 An in vitro steady flow model of mitral regurgitation by three-dimensional Doppler

1999 ◽  
Vol 1 ◽  
pp. S86-S86
Author(s):  
R DESIMONE ◽  
G GLOMBITZA ◽  
C VAHL ◽  
H MEINZER ◽  
S HAGL
Keyword(s):  
Mitral Regurgitation ◽  
Steady Flow ◽  
Flow Model ◽  
Three Dimensional

scholarly journals The Hydromechanical Interplay in the Simplified Three-Dimensional Limit Equilibrium Analyses of Unsaturated Slope Stability

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 73
Author(s):  
Panagiotis Sitarenios ◽  
Francesca Casini
Keyword(s):  
Analytical Solution ◽  
Slope Stability ◽  
Slope Failure ◽  
Failure Modes ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Three Dimensional ◽  
Stability Limit ◽  
Smooth Transition

This paper presents a three-dimensional slope stability limit equilibrium solution for translational planar failure modes. The proposed solution uses Bishop’s average skeleton stress combined with the Mohr–Coulomb failure criterion to describe soil strength evolution under unsaturated conditions while its formulation ensures a natural and smooth transition from the unsaturated to the saturated regime and vice versa. The proposed analytical solution is evaluated by comparing its predictions with the results of the Ruedlingen slope failure experiment. The comparison suggests that, despite its relative simplicity, the analytical solution can capture the experimentally observed behaviour well and highlights the importance of considering lateral resistance together with a realistic interplay between mechanical parameters (cohesion) and hydraulic (pore water pressure) conditions.

Advances in coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery

2020 ◽  
pp. 095441002096645
Author(s):  
Jie Gao ◽  
Chunde Tao ◽  
Dongchen Huo ◽  
Guojie Wang
Keyword(s):  
Performance Improvement ◽  
High Efficiency ◽  
Three Dimensional ◽  
Great Influence ◽  
Aerodynamic Characteristics ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Axial Turbine ◽  
Flow Interactions ◽  
And Performance

Marine, industrial, turboprop and turboshaft gas turbine engines use nonaxisymmetric exhaust volutes for flow diffusion and pressure recovery. These processes result in a three-dimensional complex turbulent flow in the exhaust volute. The flows in the axial turbine and nonaxisymmetric exhaust volute are closely coupled and inherently unsteady, and they have a great influence on the turbine and exhaust aerodynamic characteristics. Therefore, it is very necessary to carry out research on coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics, so as to provide reference for the high-efficiency turbine-volute designs. This paper summarizes and analyzes the recent advances in the field of coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery. This review covers the following topics that are important for turbine and volute coupled designs: (1) flow and loss characteristics of nonaxisymmetric exhaust volutes, (2) flow interactions between axial turbine and nonaxisymmetric exhaust volute, (3) improvement of turbine and volute performance within spatial limitations and (4) research methods of coupled turbine and exhaust volute aerodynamics. The emphasis is placed on the turbine-volute interactions and performance improvement. We also present our own insights regarding the current research trends and the prospects for future developments.

Experimental investigation on the three-dimensional flow field from a meltblowing slot die

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 724-732
Author(s):  
Changchun Ji ◽  
Yudong Wang
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Great Influence ◽  
Distribution Characteristics ◽  
Air Velocity ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Airflow Distribution ◽  
Slot Die ◽  
Center Area

AbstractTo investigate the distribution characteristics of the three-dimensional flow field under the slot die, an online measurement of the airflow velocity was performed using a hot wire anemometer. The experimental results show that the air-slot end faces have a great influence on the airflow distribution in its vicinity. Compared with the air velocity in the center area, the velocity below the slot end face is much lower. The distribution characteristics of the three-dimensional flow field under the slot die would cause the fibers at different positions to bear inconsistent air force. The air velocity of the spinning centerline is higher than that around it, which is more conducive to fiber diameter attenuation. The violent fluctuation of the instantaneous velocity of the airflow could easily cause the meltblowing fiber to whip in the area close to the die.

scholarly journals Engineering Comprehensive Model of Complex Wind Fields for Flight Simulation

Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 145
Author(s):  
Jianwei Chen ◽  
Liangming Wang ◽  
Jian Fu ◽  
Zhiwei Yang
Keyword(s):  
Wind Field ◽  
Three Dimensional ◽  
Great Influence ◽  
Spatial Location ◽  
Flight Simulation ◽  
Comprehensive Model ◽  
Flight Trajectory ◽  
Wind Fields ◽  
Wind Field Simulation ◽  
Low Level Jet

A complex wind field refers to the typical atmospheric disturbance phenomena existing in nature that have a great influence on the flight of aircrafts. Aimed at the issues involving large volume of data, complex computations and a single model in the current wind field simulation approaches for flight environments, based on the essential principles of fluid mechanics, in this paper, wind field models for two kinds of wind shear such as micro-downburst and low-level jet plus three-dimensional atmospheric turbulence are established. The validity of the models is verified by comparing the simulation results from existing wind field models and the measured data. Based on the principle of vector superposition, three wind field models are combined in the ground coordinate system, and a comprehensive model of complex wind fields is established with spatial location as the input and wind velocity as the output. The model is applied to the simulated flight of a rocket projectile, and the change in the rocket projectile’s flight attitude and flight trajectory under different wind fields is analyzed. The results indicate that the comprehensive model established herein can reasonably and efficiently reflect the influence of various complex wind field environments on the flight process of aircrafts, and that the model is simple, extensible, and convenient to use.

scholarly journals Analysis of Turn-to-Turn Fault on Split-Winding Transformer Using Coupled Field-Circuit Approach

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1314
Author(s):  
Cunxiang Yang ◽  
Yiwei Ding ◽  
Hongbo Qiu ◽  
Bin Xiong
Keyword(s):  
Low Voltage ◽  
Short Circuit ◽  
Three Dimensional ◽  
Great Influence ◽  
Normal Operation ◽  
Transient Field ◽  
Axial Forces ◽  
Leakage Field ◽  
Characteristics Analysis ◽  
Split Winding

The turn-to-turn faults (TTF) are also inevitable in split-winding transformers. The distorted leakage field generated by the TTF current results in large axial forces and end thrusts in the fault windings as well as affecting other branch windings normal operation, so it is of significance to study TTF of split-winding transformers. In this paper, the characteristics analysis of the split-winding transformer under the TTFs of the low voltage winding at different positions are presented. A 3600 KVA four split-windings transformer is taken as an example. Then, a simplified three-dimensional simplified model is established, taking into account the forces of the per-turn coil. The nonlinear-transient field-circuit coupled finite element method is used for the model. The leakage field distribution under the TTFs of the low voltage winding at different positions is studied. The resultant force of the short-circuit winding and the force of the per-turn coil are obtained. Subsequently, the force and current relationship between the branch windings are analyzed. The results show that the TTF at the specific location has a great influence on the axial windings on the same core, and the distorted leakage magnetic field will cause excessive axial force and end thrust of the normal and short-circuit windings. These results can provide a basis for the short-circuit design of split-winding transformer.

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