Title 



Dispersion in the wake of a rectangular building : validation of two Reynoldsaveraged NavierStokes modelling approaches
 
Author 



 
Abstract 



When modelling the turbulent dispersion of a passive tracer using Reynoldsaveraged NavierStokes (RANS) simulations, two different approaches can be used. The first consists of solving a transport equation for a scalar, where the governing parameters are the mean velocity field and the turbulent diffusion coefficient, given by the ratio of the turbulent viscosity and the turbulent Schmidt number Sc (t) . The second approach uses a Lagrangian particle tracking algorithm, where the governing parameters are the mean velocity and the fluctuating velocity field, which is determined from the turbulence kinetic energy and the Lagrangian time T (L) . A comparison between the two approaches and windtunnel data for the dispersion in the wake of a rectangular building immersed in a neutral atmospheric boundary layer (ABL) is presented. Particular attention was paid to the influence of turbulence model parameters on the flow and concentration field. In addition, an approach to estimate Sc (t) and T (L) based on the calculated flow field is proposed. The results show that applying modified turbulence model constants to enable correct modelling of the ABL improves the prediction for the velocity and concentration fields when the modification is restricted to the region for which it was derived. The difference between simulated and measured concentrations is smaller than 25% or the uncertainty of the data on 76% of the points when solving the transport equation for a scalar with the proposed formulation for Sc (t) , and on 69% of the points when using the Lagrangian particle tracking with the proposed formulation for T (L) .   
Language 



English
 
Source (journal) 



Boundarylayer meteorology.  Dordrecht  
Publication 



Dordrecht : 2010
 
ISSN 



00068314
 
Volume/pages 



137:1(2010), p. 115133
 
ISI 



000281712500006
 
Full text (Publishers DOI) 


  
Full text (open access) 


  
