scholarly journals Simulation Analysis of Vertical Movement of Nitrate Nitrogen in Vadose Zone of Fluvo-aquic Soil Based on HYDRUS-1D

2021 ◽  
Vol 293 ◽  
pp. 02008
Author(s):  
Ping Jing ◽  
Hui Zhang
Keyword(s):  
Nitrate Nitrogen ◽  
Simulation Analysis ◽  
Model Simulation ◽  
Pearson Correlation ◽  
Soil Column ◽  
Wastewater Reuse ◽  
Stable State ◽  
Ground Surface ◽  
Linear Increase ◽  
Hydrus 1D

Wastewater reuse has significant social, economic and ecological benefits, and has become an important measure to alleviate the water crisis. In this paper, in the simulation analysis of soil nitrate nitrogen, the method of combining soil column leaching and model simulation is used to test the accuracy of the model. The Pearson correlation coefficient is as high as 0.99 and the Nash coefficient is also over 0.9. It shows that the simulation results of the simulation model are credible. The Hydrus-1D model is used to visually simulate the change process of Tianjin fluvo-aquic soil over time. In the simulation, the process of solute migration in the 6-18 cm of the ground surface is basically the same, and they all reach a stable state about 4 hours, and show a linear increase trend four hours ago, and then the concentration remains stable and unchanged.

scholarly journals Dynamic analysis of material motion using MATLAB/Simulation environment and test verification

2020 ◽  
Vol 12 (9) ◽  
pp. 168781402095780
Author(s):  
Mei Fang ◽  
Zhihong Yu ◽  
Wenjie Zhang
Keyword(s):  
Dynamic Analysis ◽  
Structural Design ◽  
Simulation Analysis ◽  
Model Simulation ◽  
Maximum Relative Error ◽  
Matlab Simulation ◽  
Simulation Results ◽  
Low Efficiency ◽  
Test Verification ◽  
The Mathematical Model

Throwing device is an important factor that directly affects the performance of chaff cutter. In this work, the dynamic analysis linked with the problem of low efficiency and residue blockage of disc knife chaff cutter is executed. Based on this perspective, the mathematical model, simulation, and testing of the material movement have been carried out. Simulations are performed in MATLAB/Simulink environment. An anemometer records the airflow velocity, which provides data for simulation analysis. The simulation results showed that during the movement along the blade, the material first performs deceleration and then accelerates; in other stages, only deceleration. And finally calculated the throwing distance. To support the presented simulations, an experimental study is conducted. The experimental results are compared with simulation results, the maximum relative error between the simulated value and the experimental value is 9.42%, which verified the correctness of the model. This research provides a theoretical basis for the structural design, parameter optimization, and matching of the chaff cutter.

Small-Scale Permanent Magnet Synchronous Wind Power System Control Method Research and Simulation Analysis

2011 ◽  
Vol 347-353 ◽  
pp. 3555-3558
Author(s):  
Peng Zhao ◽  
Wen Yi Li ◽  
Xuan He ◽  
Xin Yao ◽  
Yin Sha Wang ◽  
...  
Keyword(s):  
Vector Control ◽  
Permanent Magnet ◽  
Output Voltage ◽  
Control Method ◽  
Simulation Analysis ◽  
Model Simulation ◽  
Permanent Magnet Synchronous Motor ◽  
Small Scale ◽  
System Control ◽  
Power System Control

Aims at the small wind generations output voltage fluctuation problems, according to the characteristics of permanent magnet synchronous generator, by the vector control methods, in MATLAB/Simulink lans established permanent magnet synchronous motor current speed 2-ring vector control simulation model. Simulation results show that, the method can improve the small wind turbine output voltage stability.

Study on Simulation and Stability Analysis of Subway Station Excavation from the Vertical Construction Well

2011 ◽  
Vol 250-253 ◽  
pp. 1243-1247
Author(s):  
Jin Shui Xie ◽  
Ming Zhou Bai ◽  
Zhao Yi Xu
Keyword(s):  
Optimization Design ◽  
Simulation Analysis ◽  
Research Result ◽  
Ground Surface ◽  
Support Structure ◽  
Vertical Well ◽  
Transfer Station ◽  
Project Optimization ◽  
Main Station ◽  
Support Methods

Beijing subway Huangzhuang stations is cross-transfer station. It has a complex tunneling structure. The characteristics of the reverse construction vertical well was been thinking in the course of excavation design. The vertical well excavation and support method, horizontal wells channel excavation and support methods, the main station pilot tunnel excavation and support methods were researched to determine in detail. In order to analysis and evaluation the feasibility of excavation and getting into hole, FLAC3D numerical simulation analysis method was applied to do simulation of the vertical well, horizontal channel and the main cavern excavation. All detail construction course of these three-part were been studied. Excavation and supporting method and progress were all included. The ground surface subsidence, deformation of support structure and strengthen structure were been got. On the condition of the vertical well support structure destruction caused by the horizontal guide hole excavation and the group cave effect caused by guiding cave excavation in main station underground building, the support structure and ground soil stability were studied. The research result gave the base technical support for the project optimization design and construction security.

Simulation of Oscillation Response of Free-Standing Object under Earthquakes

2011 ◽  
Vol 105-107 ◽  
pp. 417-422
Author(s):  
Qian Zhou ◽  
Wei Ming Yan
Keyword(s):  
Friction Coefficient ◽  
Simulation Analysis ◽  
Initial Conditions ◽  
Model Simulation ◽  
Dynamic Balance ◽  
Earthquake Intensity ◽  
Free Standing ◽  
Motion Equations ◽  
Object A ◽  
Simulink Model

To protect free-standing object,a rectangular object is taken as example and by SIMULINK technique its oscillation response under earthquakes were studied.Based on static and dynamic balance theories,oscillation conditions as well as motion equations of the free-standing object under earthquakes were deduced;Based on SIMULINK model,simulation analysis on the object under both level and vertical earthquakes were carried out,parameters such as initial conditions,earthquake intensity and ratio of width of the object against its height (B/H) and so on were discussed.Results show that under earthquakes oscillation conditions of the object relate closely to B/H,earthquake intensity and friction coefficient between object and its base;Under earthquakes oscillation response of the object is sensitive to initial conditions,and the response becomes more serious under less B/H or larger earthquake intensity conditions.Besides, SIMULINK technique can effectively simulate oscillation response of free-standing object under earthquakes,which proves the technique useful.

Numerical Simulation on Characteristics of Nitrate Nitrogen Leaching under Different Irrigation Levels

2014 ◽  
Vol 662 ◽  
pp. 153-159
Author(s):  
Shu Hua Ji ◽  
Jiang Yang Deng
Keyword(s):  
Numerical Simulation ◽  
Simulation Experiment ◽  
Nitrate Nitrogen ◽  
Soil Column ◽  
Nitrogen Leaching ◽  
Intensity Level ◽  
Irrigation Amount ◽  
Irrigation Level ◽  
Irrigation Intensity ◽  
Irrigation Levels

The characteristics of nitrate nitrogen leaching in soil under different irrigation levels were studied by soil column simulation experiment with numerical simulation done using LEACHM model taking nitrate nitrogen leaching under different irrigation levels as the research background. In sandy soils, an irrigation amount of 300 mm would cause nitrate nitrogen to leach downward 75~150 cm, with a leaching amount of 10~30.7 kg/ha; and an irrigation amount of 700 mm would make nitrate nitrogen leach downward about 3.5 m, with a leaching amount of 98 kg/ha. Research data showed that the amount of nitrate nitrogen leaching was positively correlated with the irrigation intensity level, irrigation level directly determined the amount of nitrate nitrogen leaching, and influenced its leaching depth.

scholarly journals Effects of Different Irrigation Strategies on Soil Water, Salt, and Nitrate Nitrogen Transport

2015 ◽  
Vol 22 (4) ◽  
pp. 589-609 ◽  
Author(s):  
Chi Xu ◽  
Wen-Zhi Zeng ◽  
Jing-Wei Wu ◽  
Jie-Sheng Huang
Keyword(s):  
Soil Water ◽  
Nitrate Nitrogen ◽  
Water Storage ◽  
Soil Water Storage ◽  
Silty Clay ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Intermittent Irrigation ◽  
Silty Loam ◽  
Hydrus 1D

Abstract Intermittent irrigation has attracted much attention as a water-saving technology in arid and semi-arid regions. For understanding the effect of intermittent irrigation on water and solute storage varied from irrigation amount per time (IRA), irrigation application frequency (IRAF), irrigation intervals (IRI) and even soil texture (ST), intermittent irrigation experiment was carried out in 33 micro-plots in Inner Mongolia, China. The experiment results were used for the calibration and validation of HYDRUS-1D software. Then 3 ST (silty clay loam, silty loam, and silty clay), 5 IRA (2, 4, 6, 8, and 10 cm), 4 IRAF (2, 3, 4, and 5 times) and 4 IRI (1, 2, 3, and 4 days) were combined and total 240 scenarios were simulated by HYDRUS-1D. Analysis of variance (ANVOA) of simulated results indicated that ST, IRA, and IRAF had significant effect on salt and nitrate nitrogen (NO3−-N) storage of 0-40 cm depth soil in intermittent irrigation while only ST affected soil water storage obviously. Furthermore, salt leaching percentage (SLP) and water use efficiency (WUE) of 0-40 cm depth were calculated and statistical prediction models for SLP were established based on the ANOVA using multiple regression analysis in each soil texture. Then constraint conditions of soil water storage (around field capacity), salt storage (smaller than 168 mg·cm−2), WUE (as large as possible) in 0-40 cm depth and total irrigation water amount (less than 25 cm) were proposed to find out the optimal intermittent irrigation strategies. Before sowing, the optimal irrigation strategy for silty clay loam soil was 6 cm IRA, 3 times IRAF, and 2 days IRI respectively. For silty loam and silty clay soils, IRA, IRAF, and IRI were 8 cm, 3 times, and 2 days respectively.

Car Seat Backrest Static Strength Experiment and Simulation

2009 ◽  
Vol 16-19 ◽  
pp. 178-182 ◽  
Author(s):  
Zhi Wei Xu ◽  
Zhong Qi Sheng ◽  
Hong Hong Zhang ◽  
Yong Xian Liu
Keyword(s):  
Finite Element ◽  
Simulation Analysis ◽  
Model Simulation ◽  
Static Strength ◽  
Analysis Model ◽  
Element Analysis ◽  
Shell Elements ◽  
Car Seat ◽  
Model And Simulation ◽  
The Cost

According to the characteristics of car seat structure and the distribution of car seat load, the finite element static strength model of the car seat is constructed in this paper. The model contains shell elements and beam elements. Some seat structure elements such as welding connection, screw connection, pin connection are simplified in the model. Simulation analysis of the static characteristics of car seat backrest frame model is carried out. At the same time, the experimental research on the static strength characteristics of the back seat is made by the measurements of non-electric physical quantities. By comparing and analyzing the results of experiment and computer simulation of seat static strength, the practicability and credibility of the seat static finite element analysis model and simplified model constructed in this paper are verified. It also proves that the simulation of various connecting forms of the seat structure is effective and is a reliable method in the structural design of the car seat. The model and simulation of the car seat can reduce the cost and shorten the design period.

Effect of crystalline lens surfaces and refractive index on image quality by model simulation analysis

2008 ◽  
Vol 6 (5) ◽  
pp. 377-380
Author(s):  
孔梅梅 孔梅梅 ◽  
Meimei Kong Meimei Kong ◽  
高志山 高志山 ◽  
Zhishan Gao Zhishan Gao ◽  
陈磊 陈磊 ◽  
...  
Keyword(s):  
Refractive Index ◽  
Image Quality ◽  
Simulation Analysis ◽  
Model Simulation ◽  
Crystalline Lens
Sign in / Sign up

Export Citation Format

Share Document