Comparison of Field Measurements and Numerical Simulations for Atmospheric Boundary Layer Flow over a Cylindrical Building

Abstract

In this study we carried out a field measurement and Fluent simulations to investigate the interaction between atmospheric boundary layer flow and the wake produced from a tall cylindrical building named Tainan FE21 In the field measurement a profiling Doppler wind LiDAR WindCube@V2 offshore was used to measure the wake produced from the building In the case study the details of the building and the LiDAR specifications will be presented Turbulence statistics of the wind data measured from the LiDAR include time-averaged horizontal wind velocity vertical velocity gradient turbulence intensity and vertical momentum flux The power spectrum analysis was carried out using the method of fast Fourier transform (FFT) to support the reliability of the wind data measured from the LiDAR In the Fluent simulations the Navier-Stokes (N-S) equations of unsteady turbulent flow were solved using the Large Eddy Simulation technique in which the Wall-Adapting Local Eddy-Viscosity (WALE) model with a constant WALE coefficient is used to parameterize the subgrid-scale (SGS) stress The hexahedral meshes are set up in the entire computational domain with a total number of approximately 2 28 million Based on the analysis of the LiDAR measurements two inflow conditions were observed and used to perform two Fluent simulations which are named Case A and Case B The comparison of the results between the field measurement and the Fluent simulations shows better agreement in the Case B study From this comparison we can conclude that the inflow conditions used in the Fluent simulations have great influence on the simulation results The inflow condition which has smaller standard deviation and is parallel to a line crossing the building position and the LIDAR deployment position will present better agreement for the comparison of the results between the field measurement and the Fluent simulations

Date of Award	2017 Jul 22
Original language	English
Supervisor	Yu-Ting Wu (Supervisor)