scholarly journals Run-out Effects of Debris Flows Based on Numerical Simulation

2016 ◽  
Vol 10 (1) ◽  
pp. 848-858
Author(s):  
Jun Wang ◽  
Yan Yu ◽  
Xinfeng Wei ◽  
Qinghua Gong ◽  
Haixian Xiong
Keyword(s):  
Numerical Simulation ◽  
Land Use ◽  
Debris Flow ◽  
Debris Flows ◽  
Flow Simulation ◽  
Simulation Method ◽  
Disaster Mitigation ◽  
Return Periods ◽  
Spatial Risk ◽  
Simulation Results

Debris flows are a common natural disaster in mountainous areas and often cause severe casualties and property loss. Debris-flow run-out effects analysis can provide an idea of the spatial risks posed to the downstream area of a debris flow, which is extremely important for local populations’ lives, disaster mitigation and planning the layout of economic construction. The objective of this study is to develop a new method to quantify debris flow run-out effects by combining debris flow simulation results and data for different types of land use within the inundated area. After a three-dimensional numerical simulation platform was established, the numerical simulation method was applied as a modeling tool to simulate the inundated areas and final buried depths under rainfalls with different return periods. The simulated result for flow depth under a 100-year return period rainfall event was validated based on field measurements. Finally, the debris-flow run-out effects under different return periods were analyzed by combining the simulation results and land use data. The proposed method can enhance the accuracy of debris-flow spatial risk assessment and has great value for application.

Numerical Simulation of the Stress Field of Thick 7B04 Aluminum Alloy Board during Continuous Manufacture Procedure

2007 ◽  
Vol 127 ◽  
pp. 259-264
Author(s):  
Hong Yuan Fang ◽  
Cheng Iei Fan
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Stress Concentration ◽  
Stress Field ◽  
Solution Treatment ◽  
Simulation Method ◽  
The Core ◽  
Manufacturing Procedure ◽  
Continuous Manufacture ◽  
Simulation Results

Numerical simulation method is employed in the article to analyze the stress field of thick 7B04 aluminum alloy board during manufacturing procedure of solution treatment, calendaring and stretching. The simulation results show that the surface of the board endures compressive stress while the core segment endures tensile stress, and the distribution of the stress is very inhomogeneous. The calendaring procedure helps to decrease the stress and redistribute the stress uniformly, but it also leads to stress concentration at the two ends of the board, which engenders bad influence on the subsequent processing. The board deforms plastically when being stretched, thus the stress decreases greatly and is redistributed uniformly.

scholarly journals Numerical Simulation Study on the Front Shape and Thermal Stresses in Growing Multicrystalline Silicon Ingot: Process and Structural Design

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1053
Author(s):  
Chengmin Chen ◽  
Guangxia Liu ◽  
Lei Zhang ◽  
Guodong Wang ◽  
Yanjin Hou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Simulation Method ◽  
Power Ratio ◽  
Radial Temperature ◽  
Front Shape ◽  
Simulation Results ◽  
Insulation Block ◽  
Transient Numerical Simulation

In this paper, a transient numerical simulation method is used to investigate the effects of the two furnace configurations on the thermal field: the shape of the melt–crystal (M/C) interface and the thermal stress in the growing multicrystalline ingot. First, four different power ratios (top power to side power) are investigated, and then three positions (i.e., the vertical, angled, and horizontal positions) of the insulation block are compared with the conventional setup. The power ratio simulation results show that with a descending power ratio, the M/C interface becomes flatter and the thermal stress in the solidified ingot is lower. In our cases, a power ratio of 1:3–1:4 is more feasible for high-quality ingot. The block’s position simulation results indicate that the horizontal block can more effectively reduce the radial temperature gradient, resulting in a flatter M/C interface and lower thermal stress.

Numerical Simulation of Engineering Wave for Zhongzui Bay

2007 ◽  
Author(s):  
Xiejun Shu ◽  
Senhui Jiang ◽  
Ruijie Li
Keyword(s):  
Numerical Simulation ◽  
Water Level ◽  
Simulation Method ◽  
High Water ◽  
Wave Transformation ◽  
Return Periods ◽  
Engineering Construction ◽  
Wave Refraction ◽  
High Water Level ◽  
Mild Slope Equation

For providing a better shelter condition, it is necessary to build a breakwater in Zhongzui Bay. In order to know whether mooring area meets the requirement after engineering construction and compare the mooring area between solid breakwater and permeable breakwater, a numerical simulation method is used in the sheltering harbor of Zhongzui Bay. The used Mild-slope equation which describes wave refraction, diffraction and reflection, considers the steep slope bottom and effect of energy dissipation. It has been validated to fit for simulating wave transformation in the coastal zone. Under extreme high water level and design high water level, wave fields in the calculation area of three wave types in three different return periods are simulated by using this method respectively. In addition, wave height in front of breakwater can be provided. Then the wave parameters and the mooring area of two occasions, with and without breakwater, are gained in calculation area. Based on these results, some conclusions are presented in the end.

Numerical Simulation of High-Temperature Air Direct-Ignition of Pulverized Coal

2005 ◽  
Author(s):  
Z. Z. Kang ◽  
B. M. Sun ◽  
Y. H. Guo ◽  
W. Zhang ◽  
H. Q. Wei
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
High Temperature ◽  
Simulation Method ◽  
Pulverized Coal ◽  
Inlet Velocity ◽  
Operation Optimization ◽  
Structure Improvement ◽  
Simulation Results ◽  
Direct Ignition

Numerical simulation method is employed in this article to investigate various high-temperature air direct-ignition processes of pulverized coal (PC). Several important factors are analyzed, which are the inlet velocity of primary air flow, PC concentration and the velocity and temperature of high temperature air. The flow, combustion and heat transfer in high temperature air oil-free ignition burner can also be obtained from the simulation results, which are in accordance with the experimental data. The research provides guidance for structure improvement and operation optimization of burner.

scholarly journals Study on Fluorine Pollution in a Slag Yard

2019 ◽  
Vol 9 (5) ◽  
pp. 847
Author(s):  
Lide Wei ◽  
Changfu Wei ◽  
Sugang Sui
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Numerical Simulations ◽  
Solute Transport ◽  
Large Scale ◽  
Three Dimensional ◽  
Simulation Method ◽  
Laboratory Studies ◽  
Survey Results ◽  
Simulation Results

This paper suggests a large-scale three-dimensional numerical simulation method to investigate the fluorine pollution near a slag yard. The large-scale three-dimensional numerical simulation method included an experimental investigation, laboratory studies of solute transport during absorption of water by soil, and large-scale three-dimensional numerical simulations of solute transport. The experimental results showed that the concentrations of fluorine from smelting slag and construction waste soil were well over the discharge limit of 0.1 kg/m3 recommended by Chinese guidelines. The key parameters of the materials used for large-scale three-dimensional numerical simulations were determined based on an experimental investigation, laboratory studies, and soil saturation of survey results and back analyses. A large-scale three-dimensional numerical simulation of solute transport was performed, and its results were compared to the experiment results. The simulation results showed that the clay near the slag had a high saturation of approximately 0.9, consistent with the survey results. Comparison of the results showed that the results of the numerical simulation of solute transport and the test results were nearly identical, and that the numerical simulation results could be used as the basis for groundwater environmental evaluation.

Effect of Plenum Chamber Configuration on Airflow Uniformity in Unidirectional Flow Cleanrooms

1994 ◽  
Vol 37 (4) ◽  
pp. 21-27
Author(s):  
Guoping Xie ◽  
Yoshihide Suwa
Keyword(s):  
Numerical Simulation ◽  
Numerical Method ◽  
Pressure Loss ◽  
Simulation Method ◽  
Calculation Domain ◽  
Plenum Chamber ◽  
Unidirectional Flow ◽  
Numerical Simulation Method ◽  
Airflow Distribution ◽  
Simulation Results

Uniformity of airflow distribution in a unidirectional flow cleanroom has been studied experimentally and numerically. The influence of the height of the plenum chamber and the velocity of airflow introduced into the chamber on the airflow uniformity are investigated experimentally. In addition, a numerical simulation method to predict airflow uniformity is proposed, taking into account the characteristics of the pressure loss of the filter. The calculation domain in this study includes not only the cleanroom but also the plenum chamber and the exhaust chamber. The validity of the numerical method is also verified by comparing the simulation results with the experiments. Finally, the numerical method is used to obtain an appropriate height for the plenum chamber.

Study on the Effect of Debris Flows from Guanba River on Qiong Lake, Sichuan, China

2012 ◽  
Vol 599 ◽  
pp. 709-715 ◽  
Author(s):  
Xue Li Wei ◽  
Yun Long Qi ◽  
Qian Gong Cheng ◽  
Ning Sheng Chen
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Environmental Problem ◽  
Water Area ◽  
Sediment Deposition ◽  
Disaster Mitigation ◽  
Mountain Slope ◽  
Change Pattern ◽  
Push Forward ◽  
Deep Water Area

Sediment deposition caused by debris flows and floods is an important process controlling the evolution and regression of lake, and even a pervasive environmental problem. Qiong Lake is regards as a “bright phearl of the altiplano” in the Yunnan Plateau, and because debris flows construct a vital links between mountain slope and Qiong Lake, so the debris flows drove by rainfall will control the evolution rule of rift lakes. Based on the data of lake shorelines of Qiong Lake, it was found that the shoreline was push forward by 665 m since 1998. In addition, in the recent 30 years, turbidity current deposits have generated underwater levee and other landscapes in the deep water area of Qiong River. This paper has analyzed the matter migration process induced by debris flows, and presented the regime change pattern of debris flow along river channel and corresponding mechanical mechanism, mainly revealed the submarine transportation and deposition pattern of debris flow. The above studies provide a helpful way of comprehending the formation mechanism of turbidity flow induced by debris flow, and the transportation pattern. Based on severe sediment deposition catastrophes in this kind of rift lakes from debris flows and floods, disaster mitigation must be planned and appropriate engineering countermeasures put in place as soon as possible.

Numerical Simulation on Temperature Distributions to Cold Store

2012 ◽  
Vol 217-219 ◽  
pp. 1460-1464 ◽  
Author(s):  
Jing Xie ◽  
Yi Tang ◽  
Jin Feng Wang ◽  
Chen Miao ◽  
Yong Yan Lin
Keyword(s):  
Numerical Simulation ◽  
Simple Algorithm ◽  
Simulation Method ◽  
Calculation Error ◽  
Cooling Process ◽  
Temperature Distributions ◽  
Cold Store ◽  
Simulation Results ◽  
Experimental Values ◽  
Simulation Condition

On the basis of previous work, the simulation condition of cold store was improved to reduce calculation error. The SIMPLE algorithm and Boussineq assumption were used and the turbulent intensity was also set. The numerical simulation results reflected that the temperature distribution was closer to the previous experimental results after using new method. The error between simulation values and experimental values was decreased. The simulation result showed that temperature of corner was highest in the cold store. The temperature change of the cold store in the cooling process could be better predicted by using modified simulation method and the accuracy of numerical simulation of cold store in the cooling process could also be validated.

A Study on the Numerical Simulation Method for the NC Incremental Sectional Forming

2014 ◽  
Vol 988 ◽  
pp. 241-244
Author(s):  
Hu Zhu ◽  
Wen Wen Lin ◽  
Jin Lan Bai
Keyword(s):  
Numerical Simulation ◽  
Digital Simulation ◽  
Simulation Method ◽  
Forming Quality ◽  
Numerical Simulation Method ◽  
Simulation Results ◽  
The Difference

The digital simulation method for NC incremental sectional forming is studied and the forming effect of NC incremental integral forming and sectional forming is analyzed through the digital simulation method in this paper. Digital simulation results show that the proposed simulation method for NC incremental sectional forming is reasonable and achievable. The difference of the forming quality between NC incremental sectional forming and integral forming is small. The sectional forming method has feasibility.

scholarly journals Numerical Simulation and Experimental Verification of Dry Pressed MgTiO3 Ceramic Body during Pressureless Sintering

2021 ◽  
Author(s):  
Jiang Wang ◽  
Yu Ni ◽  
Kai Liu ◽  
Yanying Du ◽  
Wei Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Grain Size ◽  
Relative Density ◽  
Ceramic Body ◽  
Simulation Method ◽  
Shrinkage Rate ◽  
Pressureless Sintering ◽  
Numerical Simulation Method ◽  
Average Grain Size ◽  
Simulation Results

Abstract To clarify the densification law of dry pressed MgTiO3 ceramic body during pressureless sintering, SOVS model modified with creep characteristics was embedded into finite element software Abaqus. The selected model can effectively express the grain boundary characteristics and densification mechanism. The change law of relative density, shrinkage rate, sintering stress and grain size of MgTiO3 cylindrical specimens were investigated by the above numerical simulation method. It showed that the average relative density of ceramic body rose from 60% to 97% and the shrinkage rate resepectively reached 17.28% and 11.99% in axial and radial direction. The average grain size increased from 1μm to 6 μm. In order to verify the accuracy of the simulation results, corresponding sintering experiments on cylindrical specimens were carried out to obtain actual sintering densities and shrinkage rates. It showed that the errors of relative density and shrinkage is below 5% and 2%. Grain growth trend was also basically consistent with the simulation results. After that, the above numerical simulation method was applied into the prediction of fabricating MgTiO3 filter with complex structure. Therefore, the present work provided a reliable numerical simulation method to predict the densification behavior of MgTiO3 ceramics during the pressureless sintering process, which was helpful to design and fabricate microwave dielectric products.

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