A Computational Fluid Dynamics Approach for Urban Area Transport and Dispersion Modeling

2005 ◽  
Vol 5 (5) ◽  
pp. 443-479 ◽  
Author(s):  
W. J. Coirier ◽  
D. M. Fricker ◽  
M. Furmanczyk ◽  
S. Kim
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Urban Area ◽  
Dispersion Modeling

NO depolluting performance of photocatalytic materials in an urban area - Part II: Assessment through Computational Fluid Dynamics simulations

2021 ◽  
Vol 246 ◽  
pp. 118091
Author(s):  
Beatriz Sanchez ◽  
Jose Luis Santiago ◽  
Alberto Martilli ◽  
Magdalena Palacios ◽  
Lourdes Núñez ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Urban Area ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Photocatalytic Materials

scholarly journals Consequences of Urban Stability Conditions for Computational Fluid Dynamics Simulations of Urban Dispersion

2007 ◽  
Vol 46 (7) ◽  
pp. 1080-1097 ◽  
Author(s):  
Julie K. Lundquist ◽  
Stevens T. Chan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Urban Area ◽  
Eddy Viscosity ◽  
Neutral Stability ◽  
Wake Region ◽  
Turbulence Parameterization ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Shear Production

Abstract The validity of omitting stability considerations when simulating transport and dispersion in the urban environment is explored using observations from the Joint Urban 2003 field experiment and computational fluid dynamics simulations of that experiment. Four releases of sulfur hexafluoride, during two daytime and two nighttime intensive observing periods (IOPs), are simulated using the building-resolving computational fluid dynamics model called the Finite Element Model in 3-Dimensions and Massively Parallelized (FEM3MP) to solve the Reynolds-averaged Navier–Stokes equations with two options of turbulence parameterizations. One option omits stability effects but has a superior turbulence parameterization using a nonlinear eddy viscosity (NEV) approach, and the other considers buoyancy effects with a simple linear eddy viscosity approach for turbulence parameterization. Model performance metrics are calculated by comparison with observed winds and tracer data in the downtown area and with observed winds and turbulence kinetic energy (TKE) profiles at a location immediately downwind of the central business district in the area labeled as the urban shadow. Model predictions of winds, concentrations, profiles of wind speed, wind direction, and friction velocity are generally consistent with and compare reasonably well to the field observations. Simulations using the NEV turbulence parameterization generally exhibit better agreement with observations. To explore further the assumption of a neutrally stable atmosphere within the urban area, TKE budget profiles slightly downwind of the urban wake region in the urban shadow are examined. Dissipation and shear production are the largest terms that may be calculated directly. The advection of TKE is calculated as a residual; as would be expected downwind of an urban area, the advection of TKE produced within the urban area is a very large term. Buoyancy effects may be neglected in favor of advection, shear production, and dissipation. For three of the IOPs, buoyancy production may be neglected entirely; for one IOP, buoyancy production contributes approximately 25% of the total TKE at this location. For both nighttime releases, the contribution of buoyancy to the total TKE budget is always negligible though positive. Results from the simulations provide estimates of the average TKE values in the upwind, downtown, downtown shadow, and urban wake zones of the computational domain. These values suggest that building-induced turbulence can cause the average turbulence intensity in the urban area to increase by as much as 7 times average upwind values, explaining the minimal role of buoyant forcing in the downtown region. The downtown shadow exhibits an exponential decay in average TKE, whereas the distant downwind wake region approaches the average upwind values. For long-duration releases in downtown and downtown shadow areas, the assumption of neutral stability is valid because building-induced turbulence dominates the budget. However, farther downwind in the urban wake region, which is found to be approximately 1500 m beyond the perimeter of downtown Oklahoma City, Oklahoma, the levels of building-induced turbulence greatly subside, and therefore the assumption of neutral stability is less valid.

Application of computational fluid dynamics for LNG vapor dispersion modeling: A study of key parameters

2009 ◽  
Vol 22 (3) ◽  
pp. 332-352 ◽  
Author(s):  
Benjamin R. Cormier ◽  
Ruifeng Qi ◽  
GeunWoong Yun ◽  
Yingchun Zhang ◽  
M. Sam Mannan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dispersion Modeling ◽  
Vapor Dispersion

scholarly journals Computational fluid dynamics analysis on the effect of flow distribution on pedestrian in urban area

2020 ◽  
Vol 834 ◽  
pp. 012030
Author(s):  
Haszeme Bin Abu Kasim ◽  
Mohd Faizal Bin Mohamad ◽  
Siti Khadijah Alias ◽  
Ahmad Hilmi Khalid ◽  
Muhd Azhar Bin Zainol ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Urban Area ◽  
Flow Distribution ◽  
Dynamics Analysis ◽  
Computational Fluid Dynamics Analysis

scholarly journals Computational fluid dynamics analysis for thermal-wind environment simulation of urban street in Hanoi city

Vestnik MGSU ◽  
2020 ◽  
pp. 368-379
Author(s):  
Le Minh Tuan ◽  
Ilkhomzhon S. Shukurov
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Urban Area ◽  
Urban Street ◽  
Thermal Wind ◽  
Thermal Environments ◽  
Computational Fluid Dynamics Analysis ◽  
Environment Simulation ◽  
Fluent Software ◽  
Air Speed

Introduction. One of the most important tasks in architecture and urban planning is to create the most optimal, comfortable and safe environment for human's live, work and leisure. This issue cannot be solved without taking into account the environment factor such as temperature and wind in a city. Modeling of the urban thermal-wind regime has been carried out to assess the temperature and air speed of the city streets of Hanoi. Materials and methods. Computational Fluid Dynamics (CFD) uses numerical methods to solve fluid mechanics equations by using a computer model to predict flow fields. In this study, author has used ANSYS 19.1 of the FLUENT software package to conduct the model analysis of urban street thermal environments. The study conducted a series of experimental procedures in urban street alleys that were oriented towards placement in the urban area of Trung Hoa Nhan Chinh in the Thanh Xuan district, Hanoi cit. Results. The highest temperatures were observed around the southeast side of the buildings in the urban area of Trung Hoa Nhan Chinh. Thus, a decrease in building density and maintaining the distance between buildings will contribute to the movement of the wind to cool city streets. Conclusions. The greatest contribution to the work has been created by using a micro-weather station. Analysis of the assessment of the surrounding buildings, landscaping, shade and human activities can recommend measurable improvement the thermal comfort of the streets.

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