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Advisor(s)
Abstract(s)
One major problem affecting rotor blade aerodynamics is dynamic stall, characterized by a series of events where transient vortex
shedding negatively affects drag and lift, leading to abrupt changes in the wing’s pitching moment. The present work focuses on the mitigation
of such effects by using a modified NACA0012 airfoil—the NACA0012-IK30 airfoil—previously used for thrust enhancement in
flapping propulsion. An experimental rig is designed to study the advantages of a deflectable leading edge on a plunging and pitching wing,
more specifically its influence on the aerodynamic coefficients over time. In the first stage, results indicate that the proposed IK30 mechanism
does mitigate the stall effects under static conditions, with stall visualization data corroborating it. Regarding time-varying conditions, the data
presents the adequacy of the proposed geometry under different plunging and pitching conditions, which, when correctly used, can mitigate or
even eradicate the adverse effects of dynamic stall experienced, leading to significant drag reductions and modest lift enhancements. In the
absence of a dynamic stall, the movable leading edge can also provide operational advantages, where it does not negatively affect drag or lift but
can reduce the pitching moment intensity by indirectly shifting the pressure center. This study contributes to the long-standing discussion on
how to mitigate the adverse effects of dynamic stall by providing an innovative yet simple solution.
Description
Keywords
Aerodynamic drag Aerodynamic stalling Drag reduction Vortex flow Adverse effect Aerodynamic coefficients Blade aerodynamic Dynamic stalls Experimental rigs Flapping propulsion Pitching moments Rotor blades Stall effects Vortex-shedding
Citation
Publisher
American Society of Civil Engineers (ASCE)