Numerical and experimental studies of wind environment in an urban morphology

• The purpose of the paper is to examine the relation between urban morphology (three-dimensional structure) and windiness. We regard a city as a porous obstacle, which is open at the top. We consider the interaction between the atmospheric boundary layer and a city to be both a function of the overall shape (silhouette or skyline) and the internal resistance to the flow caused by the friction when the wind flows over the urban surfaces. We regard the street pattern as an interconnected flow network with the crossings as nodes. Flow, along the streets is generated by pressure differences. We here use a highly idealized city model consisting of a circular block divided into two or four equally large sectors. Two types of cases are studied, the first with only one street through the city model with different angles between the street and the oncoming wind. The second case also contains a perpendicularly crossing street (through the center). Both wind tunnel experiments and numerical flow computations (computational fluid dynamics, CFD) are used and compared. The general agreement between the two is good and the CFD method offers new possibilities for quantifying the urban wind environment.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

Keyword

city model

street canyon

boundary layer

wind tunnel

computer simulation

mean winds

flow

roughness

canopy

areas

Publication and Content Type

ref (subject category)

art (subject category)