Ioannis Bouras
The University of Sheffield, UK
Title: The effect of grid resolution on large – eddy – simulations for the atmospheric boundary layer
Biography
Biography: Ioannis Bouras
Abstract
Air flow around a building has been simulated by employing LES and Smirnov’s inflow generation technique. Accurate inflow data for LES are of paramount importance in order to obtain reliable results for the air velocity and turbulence levels. Otherwise, the flow shows a laminar behavior regardless of the Reynolds number and it requires several characteristic lengths to be recovered. Further, the initialization of the flow is among the top problems in wind engineering. In large eddy simulations, velocity and turbulence profiles provide detailed information which are necessary for the wind resource assessment of wind turbines or wind farms that are positional at any height throughout the atmospheric boundary layer from any commercial CFD software. One of the biggest problems with LES is that the turbulence throughout the inlet of the computational domain must be fully prescribed. The present work shows the characteristics of the flow around a building by employing Smirnov’s random flow generation technique for the inflow generation data. This study is a part of the European Project New innovative solutions, components and tools for the integration of wind energy in urban and peri-urban areas (acronym SWIP, project no. 608554). The building is located in Saragossa in Spain, where a wind turbine will be installed. The energy spectrum is analyzed at different locations in the computational domain and the velocity fluctuations generated initially at the inlet and throughout the entire domain are proven to maintain the turbulence within the entire computational domain. This is also confirmed by the distribution of normal and shear Reynolds stresses throughout the domain. Finally, the present work illustrates the effect of the grid resolution on the results.