Date of Award
Fall 2022
Document Type
Open Access Thesis
Department
Mechanical Engineering
First Advisor
Michael A. Sutton
Abstract
A novel hybrid experimental-computational study is performed to predict the flow fields and pressure distributions on the measured shapes of flexible, three-tab asphalt roofing shingles undergoing increasing uplift when exposed to hurricane velocity winds. StereoDIC analysis is performed to measure the transient full-field deformed shapes of full-size three-tab asphalt shingles when subjected to hurricane velocity winds for two hours. Steady state computational fluid dynamics (CFD) simulations of the shingled roof facsimile-plenum region representative of the experiments are successfully performed. The simulations are performed to predict wind loading of the uplifted shingle shapes by utilizing the measured full-field three-dimensional uplifted shapes of the roofing shingles at different time instances. Simulation predictions clearly show flow recirculation on both the front and top of the shingles, with the recirculation regions controlling the full-field uplifting pressure distribution. For low velocities, the predicted pressures from the CFD simulations are found to be in good agreement with prior measurements at corresponding locations where shingle uplift is ≤ 8.4mm. For both low and high-speed flows, the model predictions indicate that high pressures are formed at the leading-edge upstream of the sealant layer, with the maximum pressure occurring along the leading-edge of the shingle near the tab cutouts. Under hurricane velocity winds, predictions indicate the leading-edge pressures are significantly higher than average values upstream of the sealant layer, increasing by ~ 55% prior to uplift and by ~26% during shingle uplift. The analysis indicates the maximum differential pressure, ΔP max = 3.7k Pa , occurs at the leading-edge for shingle uplift of 11.2 mm, with a slight decrease in pressure predicted for uplift > 11.2 mm. The combined experimental-computational studies provide a contemporary way to eliminate the difficulties associated with attachment of pressure sensors to flexible materials that can alter shingle response, while clearly delineating the physical processes of flow separation bubble formation and evolution that control asphalt shingle pressure loading and shingle uplift when exposed to hurricane velocity wind conditions.
Rights
© 2022, Troy A. Myers
Recommended Citation
Myers, T. A.(2022). A Hybrid Experimental-Computational Study: Prediction of Flow Fields and Full-Field Pressure Distributions on Three-Tab Asphalt Roofing Shingles Subjected to Hurricane Velocity Winds. (Master's thesis). Retrieved from https://scholarcommons.sc.edu/etd/7120