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Boundary-Layer Meteorol (2010) 136:285299 DOI 10.1007/s10546-010-9508-x
ARTICLE
Synthetic-Eddy Method for Urban Atmospheric Flow Modelling
D. Pavlidis G. J. Gorman J. L. M. A. Gomes
C. C. Pain H. ApSimon
Received: 13 April 2009 / Accepted: 12 May 2010 / Published online: 28 May 2010 Springer Science+Business Media B.V. 2010
Abstract The computational uid dynamics code Fluidity, with anisotropic mesh adaptivity, is used as a multi-scale obstacle-accommodating meteorological model. A novel method for generating realistic inlet boundary conditions based on the view of turbulence as a superposition of synthetic eddies is adopted. It is able to reproduce prescribed rst-order and second-order one-point statistics and turbulence length scales. The aim is to simulate an urban boundary layer. The model is validated against two standard benchmark tests: a plane channel ow numerical simulation and a ow past a cube physical simulation. The performed large-eddy simulations are in good agreement with both reference models giving condence that the model can be used to successfully simulate urban atmospheric ows.
Keywords Adaptive mesh Inlet boundary conditions Large-eddy simulation
1 Introduction
In a limited-area numerical ow simulation, the inlet boundary conditions account for any inuence upwind of the area of interest that is not included in the computational domain. To a large extent, they determine the solution inside the computational domain (Franke et al. 2007). Therefore, their treatment and prescription need to be carefully considered before they are applied.
In Reynolds-averaged NavierStokes (RANS) methods the mean velocity prole and information about the turbulence quantities kinetic energy (k) and energy dissipation rate () are required for a k model (Franke et al. 2007). In large-eddy simulation (LES) and direct
numerical simulation methods the procedure of generating realistic inlet boundary conditions is somewhat more complicated since time dependent boundary conditions are required.
D. Pavlidis (B) G. J. Gorman J. L. M. A. Gomes C. C. Pain
Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, UK e-mail: [email protected]
H. ApSimonCentre for Environmental Policy, Imperial College London, London SW7 2AZ, UK
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A number of techniques have been successfully applied for a wide range of applications, and the most fundamental ones are briey reviewed here.
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