Active load control for airfoils using microtabs

Micro-electro-mechanical (MEM) translational tabs are introduced for active load control on aerodynamic surfaces such cis wind turbine rotor blades. M icrotabs are mounted near the trailing edge of rotor blades, deploy approxi mately normal to the surface, and have a maximum deployment height on the o rder of the boundary-layer thickness. Deployment of the tab effectively cha nges the sectional chamber of the rotor blade, thereby changing its aerodyn amic characteristics. A tab with tab height to blade section chord ratio, h /c, of 0.01 causes an increase in the section lift coefficient, C-1, of app roximately 0.3, with minimal drag penalty. This paper presents a proof of c oncept microtab design and the multi-disciplinary techniques used to fabric ate and test the tabs. Computational and experimental wind tunnel results f or a representative airfoil using fixed as well as remotely actuated tabs a re compared. Although the specifics of load control limitations, including actuation and response tinies will require further research, the results pr esented demonstrate the significant potential for using microtabs for activ e load control.