Original scientific paper
EVALUATION OF NUMERICAL FLOW AND DISPERSION SIMULATIONS FOR STREET CANYONS WITH AVENUE-LIKE TREE PLANTING BY COMPARISON WITH WIND TUNNEL DATA
Christof Gromke
; Laboratory of Building- and Environmental Aerodynamics, Institute for Hydromechanics, University of Karlsruhe, Kaiserstr. 12, 76128 Karlsruhe, Germany
Riccardo Buccolieri
; Dipartimento di Scienza dei Materiali, University of Salento, Via Monteroni, 73100 Lecce, Italy
Silvana Di Sabatino
; Dipartimento di Scienza dei Materiali, University of Salento, Via Monteroni, 73100 Lecce, Italy
Bodo Ruck
; Laboratory of Building- and Environmental Aerodynamics, Institute for Hydromechanics, University of Karlsruhe, Kaiserstr. 12, 76128 Karlsruhe, Germany
Abstract
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 perpendicular approaching boundary layer flow. Numerical simulations have been performed with the commercial
CFD code FLUENT™ by employing the RSM turbulence model. In the presence of tree planting, both measurements and
simulations show considerable larger pollutant concentrations in proximity of the leeward wall and slightly lower concentrations in
proximity of the windward wall in comparison to the tree-less street canyon. In particular, FLUENT slightly underestimated
pollutant concentrations in proximity of the leeward wall in all cases studied, while near the windward wall there is no general
tendency towards underestimation or overestimation. Overall, numerical computations compare qualitatively well with experimental
data. Results from commonly used statistical tests also suggest the CFD predictions to be satisfactory. Results obtained in this work
by combining wind tunnel experiments and CFD based simulations in a novel aspect of research suggest ways to obtain quantitative
information for planning and implementation of exposure mitigation using trees in urban street canyons.
Keywords
street canyon; tree planting; pollutant dispersion; wind tunnel; CFD
Hrčak ID:
64271
URI
Publication date:
12.12.2008.
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