Concentration and flow distributions in urban street canyons: wind tunnel and computational data

Chang, Cheng‐Hsin; Meroney, Robert N.

doi:10.1016/s0167-6105(03)00056-4

Cited by 165 publications

(65 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Particularly susceptible to excessive air pollutant concentrations in the air are the areas located within the street canyons [1][2][3][4]. This can be explained by the occurrence of specific air circulation conditions that are not conducive to unhindered dispersion of pollutants emitted from the road transport [5][6].…”

Section: Introductionmentioning

confidence: 99%

Re-entrained road dust PM10 emission from selected streets of Krakow and its impact on air quality

Bogacki

Mazur

Oleniacz

et al. 2018

E3S Web of Conferences

View full text Add to dashboard Cite

Abstract. Scientific research studies conducted in various parts of the world confirm that PM10 concentrations in urban air depend to a great extent on the resuspension processes of the dust deposited on the road surface. The paper presents the results of the study related to the determination of the re-entrained PM10 emissions from four selected streets of Krakow (Southern Poland) together with the assessment of its impact on air quality. Examined streets are characterised by different traffic intensity (from 500 to over 20 000 vehicles per day) and individual vehicle structure. Dust material sampling and estimation of the PM10 emission were conducted according to the U.S. EPA methodology (AP 42 Fifth Edition). Two variants of sample collection were applied: from the road surface including the area at the curb (4 streets) and from the road surface alone (1 street). The estimates of resuspended road dust emission as well as the reference values derived from the U.S. EPA guidelines were used to assess the impact of this emission on the PM10 levels in the air at the location of one of the analysed streets. This assessment was conducted using the CALINE4 mathematical model. The study showed that the PM10 emissions from the re-entrained road dust can be responsible for up to 25 % in the winter and 50 % in the summer of the total PM10 concentrations in the air near the roads.

show abstract

Section: Introductionmentioning

confidence: 99%

Re-entrained road dust PM10 emission from selected streets of Krakow and its impact on air quality

Bogacki

Mazur

Oleniacz

et al. 2018

E3S Web of Conferences

View full text Add to dashboard Cite

show abstract

“…The flows are divided into the following three regimes: isolated roughness (H/W⁄0.3), wake interface (0.3⁄H/W⁄0.65), and skimming flow (0.65⁄H/W). Analogously, a wind tunnel test was performed by Chang and Meroney (2003), and found that the skimming flow (H/W= =1), wake interface (H/W= =0.25), and isolated roughness (H/W= =0.167) were also observed in 3D urban street canyons (Liu et al, 2011). It was supposed that the flow regime between the double noisebarriers is similar to that of the street canyon, with Fig.…”

Section: Evaluation Of Cfd Model Performancementioning

confidence: 86%

Effect of Double Noise-Barrier on Air Pollution Dispersion around Road, Using CFD

Jeong¹

2014

Asian J. Atmos. Environ

View full text Add to dashboard Cite

Noise-barriers on both sides of the roadway (hereafter referred to as double noise-barriers), are a common feature along roads in Korea, and these are expected to have important effects on the near-road air pollution dispersion of vehicle emissions. This study evaluated the double noise-barrier impact on near-road air pollution dispersion, using a FLUENT computational fluid dynamics (CFD) model. The realizable k-ε model in FLUENT CFD code was used to simulate vehicle air pollutant dispersion, in around 11 cases of double noise-barriers. The simulated concentration profiles and surface concentrations under no barrier cases were compared with the experimental results. The results of the simulated flows show the following three regimes in this study: isolated roughness (H/W= =0.05), wake interface (H/W= =0.1), and skimming flow (H/W¤ 0.15). The results also show that the normalized average concentrations at surface (z= =1 m) between the barriers increase with increasing double noisebarrier height; however, normalized average concentrations at the top position between the barriers decrease with increasing barrier height. It was found that the double noise-barrier decreases normalized average concentrations of leeward positions, ranging from 0.8 (H/W= =0.1, wake interface) to 0.1 (H/W = =0.5, skimming flow) times lower than that of the no barrier case, at 10 x/h downwind position; and ranging from 1.0 (H/W= =0.1) to 0.4 (H/W= =0.5) times lower than that of the no barrier case, at 60 x/h downwind position.

show abstract

“…The main approaches to predict the wind environment around buildings are field measurements, wind tunnel tests, and numerical simulation (Stathopoulos and Baskaran, 1996;Chang and Meroney, 2003). At present, there are still some errors in predicting the subtle pressures of building surfaces using numerical simulation, but the overall wind environment has been simulated with high accuracy and practical value (Stathopoulos and Baskaran, 1996;Cochran and Irwin, 1999).…”

Section: Introductionmentioning

confidence: 99%

“…Stathopoulos and Baskaran (1996) applied numerical simulation to a group of seven rectangular and parallel buildings and found that the resulting wind velocity distribution around the buildings was in good agreement with wind tunnel test results. Chang and Meroney (2003) applied Fluent (a computer software program) and four different k-ε models (turbulent models) to calculate the vortex condition within a street canyon where high-rise residential buildings were arranged in parallel, analyzing the influence of the width-height ratio of the building. Stathopoulos (1997) studied the influence of variation in the height of buildings on wind velocity around the streets using a wind tunnel test.…”

Section: Introductionmentioning

confidence: 99%

Developing planning indicators for outdoor wind environments of high-rise residential buildings

Ying

Ding

et al. 2016

J. Zhejiang Univ. Sci. A

View full text Add to dashboard Cite

Abstract:The construction of a building may change the microclimate in the vicinity, and planning indicators in a master plan may directly affect the outdoor physical environmental quality in residential areas. An inappropriate plan for a site may accelerate wind and intensify vortexes over places on the pedestrian levels, which leads to an adverse outdoor environment. Therefore, the design of a cluster of buildings should not focus only on the buildings but also provide a good outdoor environment around the buildings. To tackle the problem of inadequate wind environment, the relationship between the building's floor area ratio and height was identified in this study as the main planning indicator to be examined on its effects on the outdoor wind environment. A computational fluid dynamics (CFD) model was hence developed to simulate the wind conditions generated by some typical site layouts with different values for planning indicators under relevant weather conditions, which were typical of those in Hangzhou, China. The simulated wind conditions are assessed using the wind speed ratio over the whole area of the building cluster at the pedestrian level. The effects on the local wind condition due to the varying of the planning indicators are discussed whilst considering the potential construction costs. The indicators resulting in better external conditions are highlighted in the conclusion as the recommendation which could be used as a rule of thumb by architects and planners at the master planning stage. The study disproves the common belief in the practice that a lower floor area ratio means fewer buildings and therefore greater external comfort. In fact, the higher the building, the greater the outdoor comfort wind zone for pedestrians. However, the increment in comfort area is limited to buildings extending from 25 to 30 levels.

show abstract

Concentration and flow distributions in urban street canyons: wind tunnel and computational data

Cited by 165 publications

References 14 publications

Re-entrained road dust PM10 emission from selected streets of Krakow and its impact on air quality

Re-entrained road dust PM10 emission from selected streets of Krakow and its impact on air quality

Effect of Double Noise-Barrier on Air Pollution Dispersion around Road, Using CFD

Developing planning indicators for outdoor wind environments of high-rise residential buildings

Contact Info

Product

Resources

About