his investigation was carried out to reveal the impact of solar radiation on wind flow structure and pollutant dispersion in an urban street canyon of aspect ratio of one using the computational fluid dynamic (cfd) technique. the simulation results (velocity and concentration data) show that heating from building wall surfaces and ground lead to strong buoyancy forces as the air is heated by th...

Wind erosion threatens soil productivity and air quality in the Columbia Plateau region of the Pacific Northwest United States. Management practices are sought that will abate erosion, but limitations exist in measuring the effectiveness of these practices in reducing erosion. Portable wind tunnels are ideal tools that can be used to assess the impact of management practices on erosion. A porta...

The effects of topography, soil moisture, wind and grazing on the emergence and survival of seedlings of Festuca spp. were examined in the steppe zone of Patagonia, Argentina. Ungrazed and grazed field treatment plots were established on a plain and a north-facing slope at the Media Luna Ranch (43" 36' S, 71" 25' W). On the leeward and windward sides of each of 15 Festuca plants, 0.1 m x 0.4 m ...

Airflow behavior and indoor/outdoor PM2.5 dispersion in different building–tree grouping patterns depend significantly on the building–tree layouts and orientation towards the prevailing wind. By using a standard k-ε model and a revised generalized drift flux model, this study evaluated airflow fields and indoor/outdoor relationships for PM2.5 resulting from partly wind-induced natural ventilat...

Flow and traffic-originated pollutant dispersion in an urban street canyon with avenue-like tree planting have been studied by means of wind tunnel and CFD investigations. The study comprises tree planting of different crown porosity, planted in two rows within a canyon of street width to building height ratio W/H = 2 and street length to building height ratio L/H = 10 exposed to a perpendicula...

This paper describes the fluid mechanics of natural ventilation by the combined effects of buoyancy and wind. Attention is restricted to transient draining flows in a space containing buoyant fluid, when the wind and buoyancy forces reinforce one another. The flows have been studied theoretically and the results compared with small-scale laboratory experiments. Connections between the enclosure...

The forced convective heat transfer at the surfaces of a cubic building in an atmospheric boundary layer is investigated with CFD. Heat transfer in the boundary layer is modelled using low-Reynolds number modelling (LRNM) and standard wall functions (SWFs). SWFs are found to overestimate the convective heat transfer coefficient (CHTC) significantly. Using a customised wall function (CWF) for te...