Stall flutter suppression of NACA 0012 airfoil based on steady blowing

This paper is devoted to solve the problem of stall flutter suppression for an absolutely divergent blade of small scale wind turbine. The blade is specially designed with absolutely divergent motions for the purpose of determining the most effective methods of active control for stall flutter suppression. A 2-DOF blade section is considered, with a simplified stall nonlinear aerodynamic model being applied. H-infinity mixed-sensitivity synthesis method with a new three-weight regulation is designed to control the time-domain instability of aeroelastic equations, with a third weight being chosen to weight complementary sensitivity for tracking problems and noise attenuation to robust stabilization in H-infinity control. Effects on flutter suppression are investigated based on different structural and external parameters. Apparent effects of H-infinity mixed-sensitivity method are displayed in the paper, when the other common intelligent control methods fail. The research provides a control way for absolutely divergent turbine blade motions.

Download Full-text

Robust Stall Flutter Suppression Using ℋ2/ℋ∞ Control

Volume 1: Active Control of Aerospace Structure; Motion Control; Aerospace Control; Assistive Robotic Systems; Bio-Inspired Systems; Biomedical/Bioengineering Applications; Building Energy Systems; Condition Based Monitoring; Control Design for Drilling Automation; Control of Ground Vehicles, Manipulators, Mechatronic Systems; Controls for Manufacturing; Distributed Control; Dynamic Modeling for Vehicle Systems; Dynamics and Control of Mobile and Locomotion Robots; Electrochemical Energy Systems ◽

10.1115/dscc2014-6337 ◽

2014 ◽

Author(s):

Sohrab Haghighat ◽

Zhiwei Sun ◽

Hugh H. T. Liu ◽

Junqiang Bai

Keyword(s):

Control Systems ◽

Current Trend ◽

Mixed Norm ◽

Robust Controller ◽

Flutter Suppression ◽

Uncertainty Model ◽

Uncertain Model ◽

Wing Structures ◽

Stall Flutter ◽

The Stability

Following the current trend in aeroelastic optimization, as wing structures have been made more flexible, active control systems such as flutter suppression systems have been widely adopted to reduce undesirable aeroelastic behaviors. The stability and the performance of flutter suppression control systems can be negatively affected as the inflow speed deviates from the nominal design value. In this work, a mixed-norm robust controller is designed to perform stall flutter suppression. A 2-dimensional nonlinear time-domain aeroservoelastic model is developed. The nonlinear equations are linearized at different flight conditions and are employed to construct an uncertainty model, which affects the nominal dynamics in an affine way. The obtained uncertain model of the aeroservoelastic system is used to design a mixed-norm H2/H∞ controller. The performance of the designed controller is compared with the performance of a non-robust H2 controller at different flight conditions. The proposed control architecture reduces the adverse effect of inflow speed variation on the performance of the closed-loop system.

Download Full-text

Robust LQR control for stall flutter suppression: A polytopic approach * *This material is based on research sponsored by the US Air Force Academy under agreement number FA7000-13-2-0002 and FA7000-13-2-0009. The authors would like to acknowledge funding from Dr. Douglas Smith through the Air Force Office of Scientific Research Flow Control and Interaction portfolio. The grant of computer resources by the DoD HPCMO is gratefully acknowledged. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the French and US Air Force Academies or the French and U.S. Governments.

IFAC-PapersOnLine ◽

10.1016/j.ifacol.2017.08.2041 ◽

2017 ◽

Vol 50 (1) ◽

pp. 11367-11372 ◽

Cited By ~ 4

Author(s):

Fabien Niel ◽

Alexandre Seuret ◽

Luca Zaccarian ◽

Casey Fagley

Keyword(s):

Flow Control ◽

Air Force ◽

Scientific Research ◽

Air Force Academy ◽

Flutter Suppression ◽

Lqr Control ◽

Us Air Force ◽

The Us ◽

Stall Flutter ◽

Computer Resources

Download Full-text

Stall flutter of NACA 0012 airfoil at low Reynolds numbers

Journal of Fluids and Structures ◽

10.1016/j.jfluidstructs.2013.04.001 ◽

2013 ◽

Vol 41 ◽

pp. 166-174 ◽

Cited By ~ 27

Author(s):

Shantanu S. Bhat ◽

Raghuraman N. Govardhan

Keyword(s):

Reynolds Numbers ◽

Low Reynolds Numbers ◽

Stall Flutter ◽

Low Reynolds ◽

Naca 0012

Download Full-text

Selection of Airfoils for Vertical Axis Wind Turbines for Low Speed, Low Altitude Regions of Central India

International Journal of Advanced Research in Computer Science and Software Engineering ◽

10.23956/ijarcsse.v7i11.450 ◽

2017 ◽

Vol 7 (11) ◽

pp. 113

Author(s):

Abhineet Singh ◽

Sonali Mitra ◽

S.V.H. Nagendra ◽

Pragyan Jain

Keyword(s):

Numerical Analysis ◽

Central India ◽

Vertical Axis ◽

College Campus ◽

Low Speed ◽

Vertical Axis Wind Turbines ◽

Low Altitude ◽

Naca 0015 ◽

Naca 0012 ◽

Selection Of

The present paper deals with the selection of airfoil profile for VAWTs which is to be installed in the college campus, located in Central India region. Both experimental and numerical analysis he been carried out for the three selected airfoils, NACA 0012, NACA 0015 & S2027. The results show a good correlation with the existing literature. Airfoil profile S2027 has been chosen which best suits our condition.

Download Full-text