A comparison of measurements and CFD model predictions for pollutant dispersion in cities

2004 ◽  
Vol 334-335 ◽  
pp. 185-195 ◽  
Author(s):  
J. Pospisil ◽  
J. Katolicky ◽  
M. Jicha
Keyword(s):  
Pollutant Dispersion ◽  
Cfd Model ◽  
Model Predictions

scholarly journals A CFD model for pollutant dispersion in rivers

2004 ◽  
Vol 21 (4) ◽  
pp. 557-568 ◽  
Author(s):  
K. Modenesi ◽  
L. T. Furlan ◽  
E. Tomaz ◽  
R. Guirardello ◽  
J. R. Núnez
Keyword(s):  
Pollutant Dispersion ◽  
Cfd Model

scholarly journals Analysis of Pollutant Dispersion in a Realistic Urban Street Canyon Using Coupled CFD and Chemical Reaction Modeling

Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 479 ◽  
Author(s):  
Franchesca Gonzalez Olivardia ◽  
Qi Zhang ◽  
Tomohito Matsuo ◽  
Hikari Shimadera ◽  
Akira Kondo
Keyword(s):  
Chemical Reaction ◽  
Street Canyon ◽  
Three Dimensional ◽  
Pollutant Dispersion ◽  
Reaction Model ◽  
Building Envelope ◽  
Surface Energy Budget ◽  
Urban Canyon ◽  
Cfd Model ◽  
Chemical Reaction Model

Studies in actual urban settings that integrate chemical reaction modeling, radiation, and particular emissions are mandatory to evaluate the effects of traffic-related air pollution on street canyons. In this paper, airflow patterns and reactive pollutant behavior for over 24 h, in a realistic urban canyon in Osaka City, Japan, was conducted using a computational fluid dynamics (CFD) model coupled with a chemical reaction model (CBM-IV). The boundary conditions for the CFD model were obtained from mesoscale meteorological and air quality models. Inherent street canyon processes, such as ground and wall radiation, were evaluated using a surface energy budget model of the ground and a building envelope model, respectively. The CFD-coupled chemical reaction model surpassed the mesoscale models in describing the NO, NO2, and O3 transport process, representing pollutants concentrations more accurately within the street canyon since the latter cannot capture the local phenomena because of coarse grid resolution. This work showed that the concentration of pollutants in the urban canyon is heavily reliant on roadside emissions and airflow patterns, which, in turn, is strongly affected by the heterogeneity of the urban layout. The CFD-coupled chemical reaction model characterized better the complex three-dimensional site and hour-dependent dispersion of contaminants within an urban canyon.

scholarly journals Urban Flow and Dispersion Simulation Using a CFD Model Coupled to a Mesoscale Model

2009 ◽  
Vol 48 (8) ◽  
pp. 1667-1681 ◽  
Author(s):  
Jong-Jin Baik ◽  
Seung-Bu Park ◽  
Jae-Jin Kim
Keyword(s):  
Wind Speed ◽  
Boundary Conditions ◽  
Mesoscale Model ◽  
Model Simulation ◽  
Pollutant Dispersion ◽  
Time Dependent ◽  
Cfd Model ◽  
Ambient Wind ◽  
Mm5 Model ◽  
Urban Flow

Abstract Flow and pollutant dispersion in a densely built-up area of Seoul, Korea, are numerically examined using a computational fluid dynamics (CFD) model coupled to a mesoscale model [fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5)]. The CFD model used is a Reynolds-averaged Navier–Stokes equations model with the renormalization group k − ɛ turbulence model. A one-way nesting method is employed in this study. MM5-simulated data are linearly interpolated in time and space to provide time-dependent boundary conditions for the CFD model integration. In the MM5 simulation, four one-way nested computational domains are considered, and the innermost domain with a horizontal grid size of 1 km covers the Seoul metropolitan area and its adjacent areas, including a part of the Yellow Sea. The NCEP final analysis data are used as initial and boundary conditions for MM5. MM5 is integrated for 48 h starting from 0300 LST 1 June 2004 and the coupled CFD–MM5 model is integrated for 24 h starting from 0300 LST 2 June 2004. During the two-day period, a high-pressure system was dominant over the Korean peninsula, with clear conditions and weak synoptic winds. MM5 simulates local circulations characterized by sea breezes and mountain/valley winds. MM5-simulated synoptic weather and near-surface temperatures and winds are well matched with the observed ones. Results from the coupled CFD–MM5 model simulation show that the flow in the presence of real building clusters can change significantly as the ambient wind speed and direction change. Diurnally varying local circulations mainly cause changes in ambient wind speed and direction in the present simulation. Some characteristic flows—such as the double-eddy circulation, channeling flow, and vertical recirculation vortex—are simulated. Pollutant dispersion pattern and the degree of lateral pollutant dispersion are shown to be complicated in the presence of real building clusters and under varying ambient wind speed and direction. This study suggests that because of the sensitive dependency of urban flow and pollutant dispersion on variations in ambient wind, time-dependent boundary conditions should be used to better simulate or predict them when the ambient wind varies over the period of CFD model simulation.

A computational fluid dynamic and experimental study of an ozone contactor

2002 ◽  
Vol 46 (9) ◽  
pp. 87-93 ◽  
Author(s):  
T. Huang ◽  
C.J. Brouckaert ◽  
M. Docrat ◽  
M. Pryor
Keyword(s):  
Experimental Study ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Gas Injection ◽  
Tracer Tests ◽  
Cfd Model ◽  
Reactor Inlet ◽  
Model Predictions ◽  
Set Up ◽  
Ozone Contactor

A computational fluid dynamic (CFD) model of an ozone contacting chamber in the Umgeni Water Wiggins Waterworks in Durban, South Africa, has been set up and verified by experimental tracer tests, as part of an investigation to optimise the control and disinfection efficiency of the contactor. The effect of gas injection was modelled by increasing the turbulent intensity at the reactor inlet. Experimental tracer responses which were used as partial verification of the model correspond very closely to model predictions.

Evaluation of CFD model predictions of local dispersion from an area source on a complex industrial site

2011 ◽  
Vol 44 (1/2/3/4) ◽  
pp. 173 ◽  
Author(s):  
Richard Hill ◽  
Alistair Arnott ◽  
Paul Hayden ◽  
Tom Lawton ◽  
Alan Robins ◽  
...  
Keyword(s):  
Industrial Site ◽  
Cfd Model ◽  
Area Source ◽  
Local Dispersion ◽  
Model Predictions

Comparing zonal and CFD model predictions of isothermal indoor airflows to experimental data

Indoor Air ◽  
2003 ◽  
Vol 13 (2) ◽  
pp. 77-85 ◽  
Author(s):  
L. Mora ◽  
A. J. Gadgil ◽  
E. Wurtz
Keyword(s):  
Experimental Data ◽  
Cfd Model ◽  
Model Predictions

scholarly journals On the subsonic and low transonic aerodynamic performance of the land speed record car, Bloodhound LSR

2021 ◽  
pp. 095441002110461
Author(s):  
Ben Evans ◽  
Jack Townsend ◽  
Oubay Hassan ◽  
Kenneth Morgan ◽  
Ron Ayers ◽  
...  
Keyword(s):  
High Speed ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Cfd Model ◽  
Cfd Modelling ◽  
Vehicle Performance ◽  
Pressure Distributions ◽  
Model Predictions ◽  
High Degree ◽  
Measured Pressure

The land speed record vehicle, Bloodhound, undertook testing at subsonic and low transonic speeds (up to Mach 0.8) at Hakskeen Pan, South Africa, during October and November of 2019. A decade of CFD-led aerodynamic design had been undertaken to produce a vehicle with the aim of minimised Mach number aerodynamic dependencies and minimised overall drag. This paper sets out and explains the measured pressure distributions with a focus on the highest speed run of Bloodhound up to a peak speed of 628 mile/h. It compares the measured aerodynamic performance with the various CFD model predictions used throughout the design process showing that, whilst localised discrepancies between CFD model and real behaviour exist, overall the Reynolds-averaged Navier–Stokes (RANS)-based CFD tools used to design the car did result in sufficiently accurate aerodynamic data to predict the overall vehicle performance to a high degree of accuracy. The work outlined in this paper, and the conclusions and recommendations drawn, form the basis for a future record attempt and the understanding of what will be required in principle to extend the World Land Speed Record to 1000 mile/h. It also provides guidance on how to effectively make use of RANS-based CFD modelling predictions for other complex, ground-interacting high-speed applications.

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