Doctor of Philosophy (PhD)
Civil and environmental engineering
This research aims to improve the resiliency of low-rise buildings during powerful windstorms by augmenting the performance of buildings’ envelopes. To improve resiliency, the accuracy of the estimated aerodynamic loads of structures is fundamental. In this pursuit, this research initiative advances the estimation of aerodynamic loads on low-rise buildings using large-scale open-jet testing and computational fluid dynamics (CFD) simulations. On the experimental side, the lack of large eddies and testing at low Reynolds numbers are two notable challenges in the commonly endorsed small-scale aerodynamic testing. On the CFD simulations’ side, considerable computational expense, inability to capture the realities of the flow-separated zone and under-resolved or unresolved eddies in the flow constitute the challenges even with the most widely accepted turbulence models. Aerodynamic models of two benchmark low-rise buildings are established for experiments and CFD simulations (the Silsoe cube and the Texas Tech University (TTU) flat-roof building). The study demonstrates that the open jet allows large-scale testing at higher Reynolds numbers. Also, exceptional turbulence contents of large eddies are realized in the open-jet testing laboratory. As such, improved mean and peak aerodynamic loads are estimated on a low-rise building.
Moreover, this research presents innovative strategies to make transient CFD simulations computationally less expensive, by altering the sub-grid scale (SGS) models in large-eddy simulations (LES), using an interpolation approach for inflow, and by adjusting the surface treatment in the computational domain. Highly promising results are obtained from the empty domain study, which ensures horizontal homogeneity with adequate turbulence content. Consequently, the investigation of surface pressures is embarked upon with the desired numerical settings. The optimal computational domain’s size is recommended in this study, which is obtained by steady-state CFD simulations. Furthermore, improvements over previously published LES results are presented that concur well with full-scale measurements. The current research sets new standards in wind engineering concerning large-scale aerodynamic testing and advanced CFD simulations.
Khaled, Md Faiaz, "Aerodynamics of Low-Rise Buildings: Large-Scale (Open Jet) Testing and CFD Simulation" (2022). LSU Doctoral Dissertations. 5870.
Available for download on Friday, May 18, 2029