scholarly journals Numerical Simulation of Temperature Decrease in Greenhouses with Summer Water-Sprinkling Roof

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2435 ◽  
Author(s):  
Jiaming Guo ◽  
Yanhua Liu ◽  
Enli Lü
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Discrete Ordinates ◽  
Multiphase Model ◽  
Temperature Decrease ◽  
Turbulent Model ◽  
Flow Rates ◽  
Symmetrical Model ◽  
Simulation Results

Decreasing the temperature of a greenhouse in summer is very important for the growth of plants. To investigate the effects of a roof sprinkler on the heat environment of a greenhouse, a three-dimensional symmetrical model was built, in which a k-ε (k-epsilon) turbulent model, a DO (Discrete Ordinates) irrational model, a Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) algorithm, and a multiphase model were used to simulate the effects of the roof sprinkler, at different flow rates. Based on the simulation results, it was found that the temperature could be further reduced under a proper sprinkle rate, and the temperature distribution in the film on the roof was more uniform. A test was conducted to verify the accuracy of the model, which proved the validity of the numerical results. The simulation results of this study will be helpful for controlling and optimizing the heat environment of a greenhouse.

Analysis and Settlement of Gypsum Rain Issue in the Wet-Type FGD

2011 ◽  
Vol 347-353 ◽  
pp. 3396-3399 ◽  
Author(s):  
Tai Lv ◽  
Kun Lu ◽  
Li Jing Song
Keyword(s):  
Numerical Simulation ◽  
Power Plant ◽  
Flue Gas ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Test Results ◽  
New Construction ◽  
Simulation Results ◽  
Secondary Air ◽  
Method Of Extraction

At present, for the most part of new construction Coal-fired units desulfurization system has canceled the GGH system in our country, using the wet chimney emissions, but when the Power plant operationed it always apper the phenomenon of “gypsum rain”. In this paper, using the method of extraction part of hot secondary air to heating clean flue gas, and use fluent for three-dimensional numerical simulation with pipeline has been transformed and before it hasn’t transformed, using the κ-ε model and SIMPLE algorithm for calculating. Through the comparison of simulation results and test results, the results indicated that using the methods of hot secondary air to heating clean flue gas to reduce gesso rain is feasible and reasonable.

Numerical Simulation of Gasoline Blending with Two Different Mixing Systems

2011 ◽  
Vol 317-319 ◽  
pp. 2107-2112
Author(s):  
Song Ying Chen ◽  
Fu Chao Xie ◽  
Jun Jie Mao
Keyword(s):  
Numerical Simulation ◽  
Reynolds Equation ◽  
Mixing Time ◽  
Three Dimensional ◽  
Momentum Equation ◽  
Moving Mesh ◽  
Mixing Models ◽  
Turbulent Model ◽  
Jet Mixing ◽  
Mixing Effects

Based on two different mixing systems: Rotary Jet Mixing (RJM) system and side-entering agitator, two kinds of three-dimensional gasoline components mixing models are established. The incompressible Reynolds equation is selected as the momentum equation and the algorithm of SIMPLE is used to simulate the jet facility. To get the mixing time, moving mesh and the standard k-ε turbulent model has been employed in the multiphase unsteady flow. The results show that the dead areas of RJM are less than side-entering agitator, and the mixing effects are much better. Furthermore, the mixing time of RJM is only 58.2s, which is 69.7% of Side-entering Agitator.

scholarly journals MEMS-Based Integrated Triaxial Electrochemical Seismometer

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1156
Author(s):  
Wenjie Qi ◽  
Bowen Liu ◽  
Tian Liang ◽  
Jian Chen ◽  
Deyong Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Ground Motion ◽  
Small Volume ◽  
Three Dimensional ◽  
Experimental Results ◽  
Good Prospect ◽  
High Symmetry ◽  
Noise Levels ◽  
Sensitivity Curves ◽  
Simulation Results

This paper presents a micro-electromechanical systems (MEMS)-based integrated triaxial electrochemical seismometer, which can detect three-dimensional vibration. By integrating three axes, the integrated triaxial electrochemical seismometer is characterized by small volume and high symmetry. The numerical simulation results inferred that the integrated triaxial electrochemical seismometer had excellent independence among three axes. Based on the experimental results, the integrated triaxial electrochemical seismometer had the advantage of small axial crosstalk and could detect vibration in arbitrary directions. Furthermore, compared with the uniaxial electrochemical seismometer, the integrated triaxial electrochemical seismometer had similar sensitivity curves ranging from 0.01 to 100 Hz. In terms of random ground motion response, high consistencies between the developed integrated triaxial electrochemical seismometer and the uniaxial electrochemical seismometer could be easily observed, which indicated that the developed integrated triaxial electrochemical seismometer produced comparable noise levels to those of the uniaxial electrochemical seismometer. These results validated the performance of the integrated triaxial electrochemical seismometer, which has a good prospect in the field of deep geophysical exploration and submarine seismic monitoring.

Numerical Simulation of the Kinetic Energy Projectile Oblique Penetration into the Concrete

2014 ◽  
Vol 989-994 ◽  
pp. 982-985
Author(s):  
Jun Chen ◽  
Xiao Jun Ye
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Kinetic Energy ◽  
Three Dimensional ◽  
Test Results ◽  
Destruction Process ◽  
3D Finite Element ◽  
Finite Element Software ◽  
Simulation Results ◽  
Target Characteristics

ANSYS-LS/DYNA 3D finite element software projectile penetrating concrete target three-dimensional numerical simulation , has been the target characteristics and destroy ballistic missile trajectory , velocity and acceleration and analyze penetration and the time between relationship , compared with the test results , the phenomenon is consistent with the simulation results. The results show that : the destruction process finite element software can better demonstrate concrete tests revealed the phenomenon can not be observed , estimated penetration depth and direction of the oblique penetration missile deflection .

Numerical Simulation Study on Air-Flow Migration Law about Vortex Air Curtain of Plane Wall Fan Drum

2012 ◽  
Vol 241-244 ◽  
pp. 1285-1292
Author(s):  
Gang Zhou ◽  
Sen Cao ◽  
De Ming Wang ◽  
Wei Min Cheng ◽  
Wen Nie
Keyword(s):  
Numerical Simulation ◽  
Control System ◽  
Simple Algorithm ◽  
Plane Wall ◽  
Dust Control ◽  
High Concentration ◽  
Air Curtain ◽  
Working Face ◽  
Simulation Results ◽  
Migration Law

Vortex air curtain of plane wall fan drum can control the diffusion of air stripping dust effectively. In order to solve the high-concentration dust problem in fully mechanized excavation face, formation mechanism of vortex air curtain was analyzed. According to fluid mechanical control equations of gas phase flow, mathematical model was established to solve air migration law of vortex air curtain in fully mechanized excavation face. By using Simple algorithm based on collocated grid and fluent software, numerical simulation of air spatial migration law of closed-end dust control in fully mechanized excavation face was carried out. The simulation results show that vortex air curtain dust control system can form dust control fan drum along driving head to the front of the roadheader driver. According to the simulation results and actual conditions of working face field, vortex air curtain suction dust control system consisted of plane wall fan drum and exhausted dust purification device in fully mechanized excavation face was designed, and after it was applied in fully mechanized excavation face, the dust concentration decreased effectively in the working face field.

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.

Study on the Principle of Yarn Splicing of Pneumatic Splicer Using Numerical Simulation

2012 ◽  
Vol 588-589 ◽  
pp. 1355-1358
Author(s):  
Xiao Xing ◽  
Guo Ming Ye
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Three Dimensional ◽  
Numerical Results ◽  
Simulation Results

During the splicing process of pneumatic splicer, the principle of yarn splicing is closely related to the flow field inside the splicing chamber. This paper presents a numerical simulation of the flow char-acteristics inside the splicing chamber of the pneumatic splicer. A three-dimensional grid and the realizable tur¬bulence model are used in this simulation. The numerical results of veloc¬ity vectors distribution inside the chamber are shown. Streamlines starting from the two air injectors are also acquired. Based on the simulation, the principle of yarn splicing of the pneumatic splicer is discussed. The airflow in the splicing chamber can be divided into three regions. In addition, the simulation results have well sup¬ported the principle of yarn splicing of pneumatic splicer claimed by the splicing chamber makers.

Numerical Simulation of the Flow Field in Cavitations Nozzle for Impinging Streams Reactor

2010 ◽  
Vol 139-141 ◽  
pp. 1048-1051 ◽  
Author(s):  
Qin Li ◽  
Hui Lin Wang ◽  
Fu Bao Li
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Surrounding Medium ◽  
Analytical Calculation ◽  
Simple Algorithm ◽  
Shear Effect ◽  
Outlet Pressure ◽  
Pressure Distributions ◽  
Strong Shear ◽  
Simulation Results

The pressure distributions in cavitations nozzle of three different structures were studied by Hydromechanics theory, the models and mashes were completed by using Gambit software, for the conditions of the inlet pressure to 20MPa and the outlet pressure to 0.1MPa, the flow field within cavitations nozzles is simulated based on the standard k-ε model and the SIMPLE algorithm with Fluent. The result of numerical simulation is consistent with that of analytical calculation. Simulation results show that the flow has a strong shear effect with the surrounding medium in the diffuser, resulting in significant negative pressure, which is conducive to the formation of cavitations bubbles. The angle nozzle is best selected for impinging streams cavitations reactor on this basis in the paper.

Numerical Simulation of Seepage Field in Aquifer under the Coal Seam

2014 ◽  
Vol 955-959 ◽  
pp. 3120-3124
Author(s):  
Kai Bian ◽  
Shi Lei Chen ◽  
Xue Yuan Li ◽  
Ying Wang Zhao
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Coal Seam ◽  
Three Dimensional ◽  
Seepage Field ◽  
Limestone Aquifer ◽  
Flow Models ◽  
Hydrogeological Parameters ◽  
Simulation Results ◽  
Technical Basis

In order to figure out seepage field in aquifer under the coal seam, the geology and hydrogeology conditions systematically of study area were analyzed, hydrogeological conceptual model was generalized, mathematical model was built, seepage field of the Taiyuan limestone aquifer was simulated with software Feflow. Simulation results show that hydrogeological parameters of Taiyuan limestone aquifer change greatly in different partitions. The model also indicates the heterogeneity of karst fissure of Taiyuan limestone aquifer. The drainage quantity is from the Ordovician limestone aquifer besides supplying from runoff of upstream and capture excretion of downstream. The research is an attempt to simulate the seepage field in aquifer under coal seam, to some extent, it also provides a technical basis for safe coal mining and as a reference for simulation constructions of three-dimensional groundwater flow models in similar coal mines.

scholarly journals Development of an MTF in ADINA and its application to the study of the Yuxi Basin effect

2021 ◽  
Author(s):  
Tiefei Li ◽  
Xueliang Chen ◽  
Zongchao Li
Keyword(s):  
Numerical Simulation ◽  
Seismic Waves ◽  
Velocity Structure ◽  
Three Dimensional ◽  
Site Effect ◽  
Lumped Mass ◽  
Explicit Finite Element ◽  
Focusing Effect ◽  
Infinite Domains ◽  
Simulation Results

AbstractA three-dimensional multitransmitting formula is developed in ADINA to simulate the input of seismic waves and the scattering of infinite domains at the same time, consistent with the progress of the explicit finite element method of lumped mass. A three-dimensional cube model is built, and a delta pulse wave is input to compare the simulation results with the analytical solutions. The simulation results show that the peak error is 0.2% of the input wave, which meets the requirements of the usual numerical simulation. This method has a certain efficiency advantage in site effect analyses of fine models for localized fields. A velocity structure model of the Yuxi Basin is built, and the associated basin effect is studied by numerical simulation. The distribution of the focusing effect is related to the structure of the narrow east-west and wide north-south features in the Yuxi Basin, and the edge effect is related to the slope of the basin base. A distribution map is given of the amplification effect of ground motion in the basin.

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