Estimating Aerodynamic Parameters of Urban-Like Surfaces with Heterogeneous Building Heights |
| |
Authors: | J T Millward-Hopkins A S Tomlin L Ma D Ingham M Pourkashanian |
| |
Institution: | 1.School of Process, Environmental and Materials Engineering,University of Leeds,Leeds,UK |
| |
Abstract: | There are many geometrical factors than can influence the aerodynamic parameters of urban surfaces and hence the vertical
wind profiles found above. The knowledge of these parameters has applications in numerous fields, such as dispersion modelling,
wind loading calculations, and estimating the wind energy resource at urban locations. Using quasi-empirical modelling, we
estimate the dependence of the aerodynamic roughness length and zero-plane displacement for idealized urban surfaces, on the
two most significant geometrical characteristics; surface area density and building height variability. A validation of the
spatially-averaged, logarithmic wind profiles predicted by the model is carried out, via comparisons with available wind-tunnel
and numerical data for arrays of square based blocks of uniform and heterogeneous heights. The model predicts two important
properties of the aerodynamic parameters of surfaces of heterogeneous heights that have been suggested by experiments. Firstly,
the zero-plane displacement of a heterogeneous array can exceed the surface mean building height significantly. Secondly,
the characteristic peak in roughness length with respect to surface area density becomes much softer for heterogeneous arrays
compared to uniform arrays, since a variation in building height can prevent a skimming flow regime from occurring. Overall
the simple model performs well against available experimental data and may offer more accurate estimates of surface aerodynamic
parameters for complex urban surfaces compared to models that do not include height variability. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|