Δημοσιεύσεις

Project Acronym: CFD-URB
Title: Computation of turbulent Flow and airborne materials Dispersion in complex URBan environments
Affiliation: national center for scientific research demokritos
Pi: Spyros Andronopoulos
Research Field: environmental sciences

Large Eddy Simulation study on the structure of turbulent flow in a complex city
by I.C. Tolias, N. Koutsourakis, D. Hertwig, G.C. Efthimiou, A.G. Venetsanos and J.G. Bartzis
Abstract:
Abstract Large Eddy Simulation (LES) of atmospheric flows has become an increasingly popular modelling approach within the last years, as it has the potential to provide deeper insight into unsteady flow phenomena. \LES\ can be improved and validated using specifically designed and well documented wind tunnel datasets. In this work, we evaluate the performance of \LES\ against a wind tunnel experiment in a semi-idealized city (“Michel-Stadt”; CEDVAL-LES database) and use the \LES\ results to study the structure of the turbulent flow at the particular urban area. The first, second and third order statistics are presented, as well as velocity frequency distributions and energy spectra. The results compare well with the experimental values. Information about special features of the flow field is also provided. A particular focus of this work is put on the influence of grid resolution on the results. Five different grids are examined and the required resolution for turbulent flow within the canopy layer is evaluated. This study reveals the strong potential of \LES\ for urban flow simulations. It is shown that \LES\ can assess highly non-Gaussian flow behaviour in street canyons, which has implications for urban ventilation, wind comfort assessment and urban design.
Reference:
Large Eddy Simulation study on the structure of turbulent flow in a complex city (I.C. Tolias, N. Koutsourakis, D. Hertwig, G.C. Efthimiou, A.G. Venetsanos and J.G. Bartzis), In Journal of Wind Engineering and Industrial Aerodynamics, volume 177, 2018.
Bibtex Entry:
@article{Tolias2018101,
 title = {Large Eddy Simulation study on the structure of turbulent flow in a complex city },
 journal = {Journal of Wind Engineering and Industrial Aerodynamics },
 volume = {177},
 number = {},
 pages = {101 - 116},
 year = {2018},
 bibyear = {2018},
 note = {},
 issn = {0167-6105},
 doi = {doi:10.1016/j.jweia.2018.03.017},
 url = {https://www.sciencedirect.com/science/article/pii/S0167610517309765},
 author = {I.C. Tolias and N. Koutsourakis and D. Hertwig and G.C. Efthimiou and A.G. Venetsanos and J.G. Bartzis},
 abstract = {Abstract Large Eddy Simulation (LES) of atmospheric flows has become an increasingly popular modelling approach within the last years, as it has the potential to provide deeper insight into unsteady flow phenomena. \{LES\} can be improved and validated using specifically designed and well documented wind tunnel datasets. In this work, we evaluate the performance of \{LES\} against a wind tunnel experiment in a semi-idealized city (“Michel-Stadt”; CEDVAL-LES database) and use the \{LES\} results to study the structure of the turbulent flow at the particular urban area. The first, second and third order statistics are presented, as well as velocity frequency distributions and energy spectra. The results compare well with the experimental values. Information about special features of the flow field is also provided. A particular focus of this work is put on the influence of grid resolution on the results. Five different grids are examined and the required resolution for turbulent flow within the canopy layer is evaluated. This study reveals the strong potential of \{LES\} for urban flow simulations. It is shown that \{LES\} can assess highly non-Gaussian flow behaviour in street canyons, which has implications for urban ventilation, wind comfort assessment and urban design. },
}