Prediction of Instantaneous High Concentration nearby Buildings : #2 Numerical Simulation by RANS model

2003 ◽  
Vol 2003.13 (0) ◽  
pp. 352-353
Author(s):  
Koichi NISHIMURA ◽  
Susumu OIKAWA
Keyword(s):  
Numerical Simulation ◽  
High Concentration ◽  
Rans Model

scholarly journals Optimization of development mode of asphalt profile control based on numerical simulation and study of its mechanism

2020 ◽  
Vol 75 ◽  
pp. 30
Author(s):  
Fulin Wang ◽  
Tao Yang ◽  
Yunfei Zhao ◽  
Yanjun Fang ◽  
Fuli Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Oil Recovery ◽  
Evaluation System ◽  
Injection Rate ◽  
Injection System ◽  
Injection Timing ◽  
High Concentration ◽  
Development Mode ◽  
Displacement Effect ◽  
Profile Control

Asphalt profile control is an effective method, which can further improve oil recovery of reservoir polymer flooded, it has a lot of advantages including high strength profile control, seal strata formation efficiency, low cost and no pollution, but there has not a perfect evaluation system for its development mode. The effect of different concentration, injection rate, radius of profile control, the timing of profile and segment combination way on the oil displacement effect of the asphalt profile control were researched using numerical simulation method on actual typical well area in Daqing oilfield, and the mechanism of asphalt profile control was studied in detail. According to the results of laboratory test, the largest Enhanced Oil Recovery (EOR) of asphalt was obtained at injection concentration 4000 mg/L, and the best combination was “high–low–high” concentration slug mode. According to the results of numerical simulation, the best concentration, injection rate, radius of profile control and injection timing were 4000 mg/L, 0.15 PV/a (Pore Volume [PV], m3), 1/2 of well spacing and 96% water cut in single slug of asphalt injection system, when the injection condition was multiple slug, the “high–low–high” slug combination mode was the best injection mode. These results could provide effective development basis for asphalt profile control after polymer flooding in thick oil layers.

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.

Numerical Simulation on Hydrogen Dispersion in Automobiles due to Storage Cylinder Failure

2011 ◽  
Author(s):  
Yan-Lei Liu ◽  
Jin-Yang Zheng ◽  
Shu-Xin Han ◽  
Yong-Zhi Zhao
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Numerical Model ◽  
Hydrogen Sensor ◽  
High Concentration ◽  
Concentration Region ◽  
Species Transport ◽  
Safety Design ◽  
Simulation Results

A numerical model for dispersion of hydrogen in hydrogen powered automobiles was established basing on finite element method with species transport and reaction module of FLUENT. And corresponding numerical simulations were done in order to analysis the dispersion of hydrogen due to leakage from different position of the storage cylinder on the automobiles. Also, the distribution of the hazard region due to hydrogen dispersion was obtained. The simulation results show that the baffle above the cylinder can accumulate the hydrogen. Therefore, the high concentration region of hydrogen exists near the baffle. The study can provide reference for hydrogen sensor placement and safety design of hydrogen powered automobiles.

Characterization and Modeling of Asphaltenes for Complex Reservoirs in Venezuela: State of the Art

2020 ◽  
Author(s):  
Fernancelys Rodriguez M.
Keyword(s):  
Numerical Simulation ◽  
Porous Media ◽  
Gas Production ◽  
Production Costs ◽  
Oil Reservoirs ◽  
Asphaltene Precipitation ◽  
High Concentration ◽  
Chemical Cleaning ◽  
Thermodynamic Behavior ◽  
Conventional Oil

Abstract Asphaltenes are complex hydrocarbon molecules that are in suspension in the oil, stabilized by resins, which may cause severe production issues at reservoir and surface conditions. High asphaltene and resin contents is one of the main characteristics of the Venezuelan unconventional oils (highly viscous oils) in the Orinoco Oil Belt. This high concentration of resins in the oil maintains the aggregates of asphaltenes dissolved in the continue oil phase avoiding asphaltene precipitation/ flocculation/deposition issues at field conditions as some Venezuelan conventional oil reservoirs located in northern Monagas State in which unfavorable resins/asphaltene (R/A) ratios promote the precipitation of asphaltenes. Conventional oil reservoirs in northern Monagas show gravitational segregation, this is the case of Carito-Mulata and Santa Barbara Field, varying from an upper zone of critical fluid behavior to a black oil zone in the lowest part of the structure in which the current pressure levels induce asphaltene precipitation, causing problems by plugging reservoirs, wells and pipelines, severely affecting oil and gas production. This causes increased production costs (chemical cleaning) and/or irreversible formation damage when reservoir pressures are less than asphaltene precipitation/flocculation onset pressures. Therefore it is necessary to characterize the asphaltene thermodynamic behavior and include this in reservoir numerical-simulation models, with the aim of increasing the reliability of the results and optimizing production strategies. Reproducing the thermodynamic behavior of asphaltenes is very complex, both experimentally and in numerical simulation, especially in terms of description and measurement of the degree of asphaltene-porous media interaction and the effect of injected fluids into the reservoir (EOR methods such as miscible/non-miscible gas injection or chemical flooding). Nevertheless, efforts have been done by the Venezuelan National Oil Company and collaborators, both at laboratory and simulation scales, to study the asphaltene thermodynamic behavior and the effect of permeability reduction in the porous media and its impact on the production profiles for complex Venezuelan reservoirs. This article presents a literature review of the Venezuelan experience for the characterization and modeling of asphaltenes for conventional and heavy oil reservoirs.

Numerical Simulation of GaInP∕AlInP Window Layer For High Concentration Photovoltaic Cells

2010 ◽  
Author(s):  
Dong-Hwan Jun ◽  
Sang Hyuk Park ◽  
Yongmin Park ◽  
Chang Zoo Kim ◽  
Ho Kwan Kang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Photovoltaic Cells ◽  
Window Layer ◽  
High Concentration

Numerical Simulation of SiO2 Fouling While Evaporating High Concentration Extracted Oil Wastewater

2012 ◽  
Vol 518-523 ◽  
pp. 3231-3235
Author(s):  
Long Sheng Zou ◽  
De Zhen Chen ◽  
Wei Guo Zhou
Keyword(s):  
Numerical Simulation ◽  
Heat Resistance ◽  
Influencing Factors ◽  
Flow Rate ◽  
Change Process ◽  
Temperature Increase ◽  
Concentration Ratio ◽  
High Concentration ◽  
Evaporation Temperature ◽  
Oil Wastewater

This article aims at fouling situation while extracted oil wastewater evaporating and has analyzed the change process in wastewater SiO2. We point out influence of the formation of fouling SiO2pre-condition—supersaturation and establish SiO2crystallization precipitation model and equation. The results show that concentration ratio and evaporation temperature increase to help fouling formation to give rise to fouling heat resistance elevating. The increase of extracted oil wastewater flow rate loop reduce the fouling heat resistance and improve the efficiency of heat utilize. Through simulation , we master main influencing factors of fouling heat resistance and grain a good foundation to design the experiment scheme in the future.

Study of Operating Parameters’ Impact on Separation Performance of Cyclone Separator

2011 ◽  
Vol 422 ◽  
pp. 794-798
Author(s):  
Xue Ping Wang ◽  
Ying Zhang ◽  
Ju Guang Xue ◽  
Zhen Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Flow Velocity ◽  
Turbulence Model ◽  
Separation Efficiency ◽  
Operating Parameters ◽  
Separation Performance ◽  
Cyclone Separator ◽  
High Concentration ◽  
Secondary Particles

The numerical simulation can be obtained by taking advantage of turbulence model of Fluent to study the gas-solid flow field of cyclone separator. The pressure of the cyclone drops increases with the enhancement of the inlet flow velocity, and the increase amplitude can become larger and larger. The separation efficiency of the cyclone enhances gradually as the increase of the flow. The increase amplitude of small and secondary particles is much lager compared with the increase amplitude of big ones. The overall separation efficiency can strengthen gradually with increasing of particles concentration as well as the each part’s efficiency. But the separation efficiency will stay in stable level when the concentration reaches a certain value with the big particles in the low concentration and small ones in a relatively high concentration.

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