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Helical Strakes On High Mast Lighting Towers And Their Effect On Vortex Shedding Lock-In, Ayah Zahour
Helical Strakes On High Mast Lighting Towers And Their Effect On Vortex Shedding Lock-In, Ayah Zahour
Open Access Theses
An experimental study on the effect of helical strakes on vortex induced vibrations and the lock-in phenomenon in High Mast Lighting Towers (HMLTs) is investigated. Two multi-sided tapered scaled models are clamped in place in a subsonic wind tunnel that is equipped with a hot-wire sensor and a traverse mechanism. The shedding frequency data is collected for the models with and without helically patterned strakes with the use of two different ropes. The responses of the tower models, for a Reynolds number of 44, 000, are compared and discussed under different configurations including: two directions of the model with respect …
Theoretical Modeling, Experimental Observation, And Reliability Analysis Of Flow-Induced Oscillations In Offshore Wind Turbine Blades, Pariya Pourazarm
Theoretical Modeling, Experimental Observation, And Reliability Analysis Of Flow-Induced Oscillations In Offshore Wind Turbine Blades, Pariya Pourazarm
Doctoral Dissertations
Offshore wind energy has been growing rapidly due to its capacity for utilizing much larger turbines and thus higher power generation compared to onshore. With the increasing size of offshore wind turbine rotors, the design criteria used for the blades may also evolve. Increased flexibility in blades causes them to be more susceptible to experiencing flow-induced instability. One of the destructive aero-elastic instabilities that can occur in flexible structures subjected to aerodynamic loading is coupled-mode flutter. Coupled-mode flutter instability has not been a design driver in the current wind turbine blades, however, considering the industry tendency in utilizing longer and …