Flow Characteristics Around Step-Up Street Canyons with Various Building Aspect Ratios

Cited 0 times inthomson ciCited 0 times inthomson ci
Flow Characteristics Around Step-Up Street Canyons with Various Building Aspect Ratios
Park, Soo-JinKim, Jae-JinChoi, WonsikKim, Eun-RyoungSong, Chang-KeunPardyjak, Eric R.
Issue Date
Kluwer Academic Publishers
BOUNDARY-LAYER METEOROLOGY, v.174, no.3, pp.411 - 431
We investigate the flow characteristics around step-up street canyons with various building aspect ratios (ratio of along-canyon building length to street-canyon width, and upwind building height to downwind building height) using a computational fluid dynamics (CFD) model. Simulated results are validated against experimental wind-tunnel results, with the CFD simulations conducted under the same building configurations as those in the wind-tunnel experiments. The CFD model reproduces the measured in-canyon vortex, rooftop recirculation zone above the downwind building, and stagnation point position reasonably well. We analyze the flow characteristics, focusing on the structural change of the in-canyon flows and the interaction between the in- and around-canyon flows with the increase of building-length ratio. The in-canyon flows undergo development and mature stages as the building-length ratio increases. In the development stage (i.e., small building-length ratios), the position of the primary vortex wanders, and the incoming flow closely follows both the upstream and downstream building sidewalls. As a result, increasing momentum transfer from the upper layer contributes to a momentum increase in the in-canyon region, and the vorticity in the in-canyon region also increases. In the mature stage (i.e., large building-length ratios), the primary vortex stabilizes in position, and the incoming flow no longer follows the building sidewalls. This causes momentum loss through the street-canyon lateral boundaries. As the building-length ratio increases, momentum transfer from the upper layer slightly decreases, and the reverse flow, updraft, and streamwise flow in the in-canyon region also slightly decrease, resulting in vorticity reduction.
Appears in Collections:
UEE_Journal Papers
Files in This Item:
Park2019_Article_FlowCharacteristicsAroundStep-.pdf Download

find_unist can give you direct access to the published full text of this article. (UNISTARs only)

Show full item record


  • mendeley


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.