Multiscale parameterisation of passive scalars via wavelet-based numerical homogenisation

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

1 Scopus Citations
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Detail(s)

Original languageEnglish
Pages (from-to)217-234
Number of pages18
Journal / PublicationApplied Mathematical Modelling
Volume82
Online published21 Jan 2020
Publication statusPublished - Jun 2020

Abstract

Wavelet-based numerical homogenisation is applied to the subgrid parameterisation of urban pollutants. Numerical homogenisation represents a promising multiscale alternative to conventional parameterisation methods because interactions between resolved and unresolved scales are preserved without restrictive assumptions. From large-eddy simulations of two idealised urban domains, a street canyon and a building array, it is shown that numerical homogenisation provides an accurate estimate of the average scalar concentration and a fair estimate of the standard deviation. Successive homogenisations generate larger scales and off-diagonal contributions to the homogenised advection-diffusion operator. Approximation methods that decrease the size of the operator and partially alleviate the significant computational requirements are evaluated. This work is applicable to the development of improved urban parameterisations for regional air quality models.

Research Area(s)

  • Building array, Computational fluid dynamics, Homogenisation, Pollutant dispersion, Street canyon, Urban canopy parameterisation