scholarly journals Assessing On-Road Emission Flow Pattern under Car-Following Induced Turbulence Using Computational Fluid Dynamics (CFD) Numerical Simulation

2019 ◽  
Vol 11 (23) ◽  
pp. 6705 ◽  
Author(s):  
Xueqing Shi ◽  
Daniel (Jian) Sun ◽  
Song Fu ◽  
Zhonghua Zhao ◽  
Jinfang Liu
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Concentration Gradient ◽  
Line Source ◽  
Car Following ◽  
Source Models ◽  
Computational Fluid Dynamics Cfd ◽  
Road Emission ◽  
Traffic Exhaust

Research assessing on-road emission flow patterns from motor vehicles is essential in monitoring urban air quality, since it helps to mitigate atmospheric pollution levels. To reveal the influence of vehicle induced turbulence (VIT) caused by both front- and rear-vehicles on traffic exhaust and verify the applicability of the simplified line source emission model, a Computational Fluid Dynamics (CFD) numerical simulation was used to investigate the micro-scale vehicle pollutant flow patterns. The simulation results were examined through sensitivity analysis and compared with the field measured carbon monoxide (CO) concentration. Conclusions indicate that the vehicle induced turbulence caused by the airflow blocking effect of both front- and rear-vehicles impedes the diffusion of front-vehicle traffic exhaust, compared with that of the rear vehicle. The front-vehicle isosurface with the CO mass fraction of 0.0012 extended to 6.0 m behind the vehicle, while that of the rear-vehicle extends as far as 12.7 m. But for the entire motorcade, VIT is beneficial to the diffusion of pollutants in car-following situations. Meanwhile, within the range of 9 m behind the rear of the lagging vehicle lies a vehicle induced turbulence zone. Furthermore, the influence of vehicle induced turbulence on traffic exhaust flow pattern is obvious within a range of 1 m on both sides of the vehicle body, where the concentration gradient of on-road emission is larger and contains severe mechanical turbulence. As a result, in the large concentration gradient area of the pollutant flow field, which accounts for 99.85% of the total concentration gradient, using the line source models to represent the on-road emission might introduce considerable errors due to neglecting the influence of vehicle induced turbulence. Findings of this study may shed lights on predicting emission concentrations in multiple locations by selecting appropriate on-road emission source models.

Numerical and Experimental Study on a Honeycomb Ceramic Monolith

2012 ◽  
Vol 532-533 ◽  
pp. 431-435
Author(s):  
Chong Zhi Mao ◽  
Qian Jian Guo ◽  
Lei He
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Experimental Study ◽  
Computational Fluid Dynamics ◽  
Flue Gas ◽  
Regenerative Process ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Honeycomb Ceramic ◽  
Oxidation Reactor

Honeycomb ceramic is the key component of the regenerative system. The numerical simulation was performed using FLUENT, a commercial computational fluid dynamics (CFD) code, to compare simulation results to the test data. The regenerative process of a honeycomb ceramic regenerator was simulated under different conditions. Experiments were carried out on honeycomb regenerators that are contained in a methane oxidation reactor. The calculated temperatures of flue gas inlet were compared with the ones measured. The tendency of the temperature is the same as the experiment.

scholarly journals Numerical Simulation of Single-Phase and Two-Phase Flows in Separator Vessels with Inclined Half-Pipe Inlet Device Applied in Reciprocating Compressors

2018 ◽  
Vol 8 (3) ◽  
pp. 2897-2900
Author(s):  
F. P. Lucas ◽  
R. Huebner
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Single Phase ◽  
Air Flow ◽  
Air Distribution ◽  
Two Phase ◽  
Computational Fluid Dynamics Cfd ◽  
Liquid Removal ◽  
Pipe Inlet

This paper aims to apply computational fluid dynamics (CFD) to simulate air flow and air flow with water droplets, as a reasonable hypothesis for real flows, in order to evaluate a vertical separator vessel with inclined half-pipe inlet device (slope inlet). Thus, this type was compared to a separator vessel without inlet device (straight inlet). The results demonstrated a different performance for the two types in terms of air distribution and liquid removal efficiency.

Simulation Based on CFD to Temperature and Flow Fields of Vertical Air Conditioner Operation

2012 ◽  
Vol 594-597 ◽  
pp. 2106-2111
Author(s):  
Yi Tang ◽  
Jin Feng Wang ◽  
Jing Xie ◽  
Zheng Zhang ◽  
Rui Liu
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Sales Volume ◽  
Air Conditioner ◽  
Meeting Room ◽  
Simulation Based ◽  
Computational Fluid Dynamics Cfd ◽  
China Mainland ◽  
Temperature And Flow Fields

The sales volume of vertical air conditioner in China mainland has developed rapidly. The researches in the field to the operation of vertical air conditioner are lacked since it is hardly to analyze different kinds of operating condition. Computational Fluid Dynamics (CFD) has been applied in engineering with the advance of the computer science and technology. In this article, both temperature and air flow distributions were analyzed to a meeting room which putted a vertical air conditioner. The model was used and the equations for numerical simulation (e.g. energy, residual, continuity, etc) were chosen as second order to get the higher accuracy. The results to simulation were showed reasonable and could offer a reference to the practical.

scholarly journals Stimulating Simulating

1997 ◽  
Vol 163 ◽  
pp. 832-833
Author(s):  
Rob Whitehurst
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Finite Difference ◽  
Accretion Discs ◽  
Particle Methods ◽  
Potential Treatment ◽  
Computational Fluid Dynamics Cfd

AbstractThe difficulties associated with numerical simulation of accretion discs are outlined along with a potential treatment, FLAME. This technique bridges the gap between existing finite difference codes and particle methods in modern computational fluid dynamics (CFD).

A Numerical Study of Flow Field in a Hydrocyclone for Potash Ore Desliming

2013 ◽  
Vol 448-453 ◽  
pp. 3847-3850
Author(s):  
Da Li ◽  
Fang Qin Cheng ◽  
Jian Feng Li ◽  
Yun Shan Guan
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Numerical Study ◽  
Numerical Approach ◽  
Basic Information ◽  
Feed Composition ◽  
Accurate Design ◽  
Computational Fluid Dynamics Cfd

Despite the widespread use of hydrocyclone in the process of potash ore desliming, its accurate design is often difficult because the feed composition is complicated and the viscosity is high in the brine system. In this study, a numerical approach based on computational fluid dynamics (CFD) was performed to describe the flow field. The numerical simulation of flow pattern in hydrocyclones for potash ore desliming was presented. Some basic information concerning the velocity and pressure distribution is given, and the results can be used as the fundamental basis for its design.

scholarly journals Numerical Simulation of Flow in Parshall Flume Using Selected Nonlinear Turbulence Models

Hydrology ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 151
Author(s):  
Mehdi Heyrani ◽  
Abdolmajid Mohammadian ◽  
Ioan Nistor
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Standard Error ◽  
Physical Modeling ◽  
Hydraulic Structure ◽  
Turbulence Models ◽  
Computational Fluid Dynamics Cfd ◽  
The Right

This study uses a computational fluid dynamics (CFD) approach to simulate flows in Parshall flumes, which are used to measure flowrates in channels. The numerical results are compared with the experimental data, which show that choosing the right turbulence model, e.g., v2−f and LC, is the key element in accurately simulating Parshall flumes. The Standard Error of Estimate (SEE) values were very low, i.e., 0.76% and 1.00%, respectively, for the two models mentioned above. The Parshall flume used for this experiment is a good example of a hydraulic structure for which the design can be more improved by implementing a CFD approach compared with a laboratory (physical) modeling approach, which is often costly and time-consuming.

Numerical Simulation of Temperature in the Freeboard of COREX Melting Gasifier

2011 ◽  
Vol 284-286 ◽  
pp. 1165-1169 ◽  
Author(s):  
Ye Sun ◽  
Zhan Xia Di ◽  
Hai Feng Li ◽  
Zhi Guo Luo ◽  
Zong Shu Zou
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Temperature Field ◽  
Operation Conditions ◽  
Important Region ◽  
Corex Melter Gasifier ◽  
Computational Fluid Dynamics Cfd ◽  
Key Parameter

The freeboard, which is an important region in COREX melter gasifier, has drawn more and more attentions, and as a key parameter for COREX melter gasifier operation, the temperature in freeboard must be within a certain range. In this paper, the temperature field of freeboard is simulated with computational fluid dynamics(CFD). The results show that the temperature in bottom is lower than that in upper. The temperature when oxygen nozzles are open is higher than that when oxygen nozzles are off, and the temperature under different operation conditions is all about 1000 °C.

Numerical Simulation of Cross-Ventilation in Buildings Affected by Surrounding Buildings with Different Separation Distances

2013 ◽  
Vol 353-356 ◽  
pp. 2993-2996 ◽  
Author(s):  
Tao Tao Shui ◽  
Jing Liu ◽  
Fei Ma
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Street Canyon ◽  
Natural Ventilation ◽  
Flow Characteristics ◽  
Airflow Rate ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Des Model

In order to investigate natural cross-ventilation in buildings, computational fluid dynamics (CFD) with the DES model is applied. The aim of this paper is to investigate the influence of surrounding buildings on natural ventilation in target building under different separation distances. The simulation results indicate that surrounding buildings has a significant impact on airflow structure and airflow rate of the target building. The flow characteristics in target building is determined by the flow regime in street canyon.

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