A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Measurement-driven Large Eddy Simulation of dispersion in street canyons of variable building height
Abstract The ventilation efficiency of three periodic building patterns of equal total volume and packing density is investigated: street canyons bounded by H uniform and 0.5H/1.5H variable height buildings, via wind tunnel measurements and Large Eddy Simulation. The numerical model utilizes the Transient Wind Forcing method to take the effect of eddies larger than the domain size into account, and a special Lagrangian dispersion model, which allows for the calculation of particle trajectories exceeding the periodic boundaries of the LES domain. The spatial and temporal characteristics of the concentration responses of both pulse-like and steady point sources located at the street surfaces are analyzed. It is shown that the variable building height has a favorable effect on urban ventilation in densely built areas: the average near-ground concentration can be reduced by up to 70% for the variable height buildings in a staggered arrangement. In terms of velocity, turbulence and concentration distributions, the model results are consistent with the experiments, verifying the applicability of the model for comparative air quality studies. Since the presented dispersion model is capable of handling dynamic changes in wind direction and magnitude, the accuracy of the TWF model can potentially overcome the limitations of wind tunnel tests.
Graphical abstract Display Omitted
Highlights Original wind tunnel experiments for three periodic building arrangements. LES driven by measured velocity data from wind tunnel tests or field experiments. The effect of large flow structures and the variable wind direction can be modeled. Aperiodic Lagrangian dispersion model based on the periodic flow field. The variable roof height can decrease the pollutant concentration by up to 70%.
Measurement-driven Large Eddy Simulation of dispersion in street canyons of variable building height
Abstract The ventilation efficiency of three periodic building patterns of equal total volume and packing density is investigated: street canyons bounded by H uniform and 0.5H/1.5H variable height buildings, via wind tunnel measurements and Large Eddy Simulation. The numerical model utilizes the Transient Wind Forcing method to take the effect of eddies larger than the domain size into account, and a special Lagrangian dispersion model, which allows for the calculation of particle trajectories exceeding the periodic boundaries of the LES domain. The spatial and temporal characteristics of the concentration responses of both pulse-like and steady point sources located at the street surfaces are analyzed. It is shown that the variable building height has a favorable effect on urban ventilation in densely built areas: the average near-ground concentration can be reduced by up to 70% for the variable height buildings in a staggered arrangement. In terms of velocity, turbulence and concentration distributions, the model results are consistent with the experiments, verifying the applicability of the model for comparative air quality studies. Since the presented dispersion model is capable of handling dynamic changes in wind direction and magnitude, the accuracy of the TWF model can potentially overcome the limitations of wind tunnel tests.
Graphical abstract Display Omitted
Highlights Original wind tunnel experiments for three periodic building arrangements. LES driven by measured velocity data from wind tunnel tests or field experiments. The effect of large flow structures and the variable wind direction can be modeled. Aperiodic Lagrangian dispersion model based on the periodic flow field. The variable roof height can decrease the pollutant concentration by up to 70%.
Measurement-driven Large Eddy Simulation of dispersion in street canyons of variable building height
Papp, Bálint (author) / Kristóf, Gergely (author) / Istók, Balázs (author) / Koren, Márton (author) / Balczó, Márton (author) / Balogh, Miklós (author)
2020-12-20
Article (Journal)
Electronic Resource
English