Numerical Investigation of Flapwise-Torsional Vibration Model of a Smart Section Blade with Microtab

Abstract

This study presents a method to develop an aeroelastic model of a smart section blade equipped with microtab. The model is suitable for potential passive vibration control study of the blade section in classic flutter. Equations of the model are described by the nondimensional flapwise and torsional vibration modes coupled with the aerodynamic model based on the Theodorsen theory and aerodynamic effects of the microtab based on the wind tunnel experimental data. The aeroelastic model is validated using numerical data available in the literature and then utilized to analyze the microtab control capability on flutter instability case and divergence instability case. The effectiveness of the microtab is investigated with the scenarios of different output controllers and actuation deployments for both instability cases. The numerical results show that the microtab can effectively suppress both vibration modes with the appropriate choice of the output feedback controller.

Stall Flutter Control of a Smart Blade Section Undergoing Asymmetric Limit Oscillations

“…0 is the static separation point at the steady angle of attack. The details of the formulation of the attached lift 1 and moment 1 can be found in the literature [25].…”

“…Controllers. Before the study of the control algorithm for stall flutter control, two former controllers that have been developed by the author in classic flutter control study [25] and pitch control study [24] are first tested on the stall flutter case. Those controllers are also developed with the actuator of the microtab.…”

“…The microtab controller was also designed to have full controllability on pitch motion [24]. Moreover, the microtab was recently investigated for the control of classic flutter at relatively small angle of attack [25].…”

Flutter suppression of blade section based on model prediction control

“…Structure modeling and stall-induced instability analysis of individual turbine blade section, subjected to combined flap-wise/lead-lag and flap-wise/twist motions, have been investigated, with extended Office National D’Etudes et de Recherches Aerospatiales aerodynamic model and Navier-Stokes model applied to analyze aeroelastic stability (Chaviaropoulos et al, 2003). Numerical investigation of flap-wise/twist vibration model of a 2D blade section integrated with microtab has been investigated, with its effectiveness performed by the scenarios of different output controllers and actuation deployments (Li et al, 2015). The effects of bending/twist coupling on the aeroelastic modal properties and stability limits of a 2D blade section in attached flow have been investigated (Stäblein et al, 2017).…”

Vibration and aeroelastic control of wind turbine blade based on B-L aerodynamic model and LQR controller

“…How to effectively realize aeroelastic control has become an important research needed to be investigated in the last few years. For the active aeroelastic control methods of blades, one category is load reduction based on structural trailing edge flap, microtab and piezoelectric actuator [1][2][3][4], the other is the direct application of intelligent control theories [5]. Although in these works, the blade properties dynamically represent a real rotor blade; the analytical object is the flap-wise or torsional behavior of a helicopter blade or the vibration behavior of a wing airfoil in which stall nonlinear flutter of BBT coupling action is not mentioned.…”