On the Flow Past an Array of Two-Dimensional Street Canyons Between Slender Buildings

摘要: The flow above idealized, two-dimensional series of parallelepipedal buildings is examined with the aim investigating how building width to height aspect ratio affects turbulence in roughness sublayer and ventilation underlying street canyons. We compare case a squared section configuration slender both unit canyon AR = 2. former corresponds skimming latter wake-interference regime. Measurements are performed water channel, measuring velocity on vertical mid-plane using particle image velocimetry technique. mean flow, its second-order statistics, exchange fluxes, integral time scales investigated, results showing that enhance production yield longer region just roof. combined analysis fields snapshots during sweep ejection events demonstrate shear layer between external significantly more unstable buildings, mainly because damping effect fluctuations from flat roof upwind substantially missing. Consequently, larger (downstream) portion interface prone direct interaction structures. higher intensity promotes at interface. In summary, present experiments show reduced particularly significant when urban canopy consists narrow result interest since canyons typically bounded by texture old European city centres.