2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference


Title
Generation of Downburst Outflows using a Multi-Blade System at Ryerson University’s Boundary Layer Wind Tunnel

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Author(s)
Mr. Moustafa Aboutabikh, Ryerson University (Presenter)
Mr. Tarek Ghazal, Ryerson University
Mr. Jiaxiang Chen, Ryerson University
Dr. Haitham Aboshosha, Ryerson University
Abstract

This study focuses on the design and validation of a blade system that allows the generation of downburst outflows at the Subsonic Wind Tunnel (WT) at Ryerson University (RU). The system is based on flow redirection to generate downburst outflow gust fronts. A louver system was designed and calibrated using CFD simulations and wind tunnel testing in 3 stages. In stage 1, flow resulting from the system with stationary inclined blades (do not move with the time) was characterized to understand formation of the outflow-like vortices. Stage 2 focuses on the non-stationary effects resulting from suddenly rotating the blades to a specific angle over a specific time. Stage 3 focuses on developing a superposition code to combine different cases from stage 2 (blades rotate to different angles). This superposition code was coupled with an optimization technique to generate arbitrary downburst outflows at the full scale. Full-scale records were selected, and optimization was carried out to identify blade angles and time simulating the records. Accuracy of the blade system and optimization was confirmed by conducting CFD simulations along with a comprehensive blade rotation as described from the optimization, and achieving well-matching records to the full scale. Based on that, the louver system was constructed, implemented at the WT and experimentally tested. It was found out that the system can generate downburst outflows matching the full-scale records with high level of accuracy. This system will be implemented to study downburst effect on structures.