Active flutter suppression of a smart fin

Karadal, Fatih Mutlu
This study presents the theoretical analysis of an active flutter suppression methodology applied to a smart fin. The smart fin consists of a cantilever aluminum plate-like structure with surface bonded piezoelectric (PZT, Lead- Zirconate-Titanate) patches. A thermal analogy method for the purpose of modeling of piezoelectric actuators in MSC®/NASTRAN based on the analogy between thermal strains and piezoelectric strains was presented. The results obtained by the thermal analogy were compared with the reference results and very good agreement was observed. The unsteady aerodynamic loads acting on the structure were calculated by using a linear two-dimensional Doublet-Lattice Method available in MSC®/NASTRAN. These aerodynamic loads were approximated as rational functions of the Laplace variable by using one of the aerodynamic approximation schemes, Roger’s approximation, with least-squares method. These approximated aerodynamic loads together with the structural matrices obtained by the finite element method were used to develop the aeroelastic equations of motion of the smart fin in state-space form. The Hinf robust controllers were then designed for the state-space aeroelastic model of the smart fin by considering both SISO (Single-Input Single-Output) and MIMO (Multi-Input Multi-Output) system models. The verification studies of the controllers showed satisfactory flutter suppression performance around the flutter point and a significant improvement in the flutter speed of the smart fin was also observed.


Active Flutter Control of a Smart Fin
Fatih Mutlu, Karadal; Volkan, Nalbantoğlu; Şahin, Melin; Güçlü, Seber; Ömer Faruk, Kırcalı; Yaman, Yavuz (null; 2008-10-06)
This study presents the theoretical analysis of an active flutter suppression methodology applied on a smart fin. The smart fin consisted of a cantilever aluminum plate-like structure with surface bonded piezoelectric (PZT, Lead- Zirconate-Titanate) patches. The robust controllers were designed via H∞ synthesis by considering both SISO (Single-Input, Single-Output) and MIMO Multi-Input, Multi-Output) aeroelastic system models. The developed controllers performed well around the flutter point and also stabil...
Implicit large eddy simulation of vitiation effects in supersonic air/H-2 combustion
Karaca, Mehmet; Zhao, Song; Fedioun, Ivan; Lardjane, Nicolas (Elsevier BV, 2019-06-01)
This paper presents and discusses Implicit Large Eddy Simulation (ILES) results of vitiation effects in ground tests of supersonic air/H-2 combustion. This work is useful for realistic extrapolation of ground test data to flight conditions. The high-enthalpy flow configuration retained, typical of scramjet engines, is the Mach 2 LAERTE combustion chamber of the French aerospace lab ONERA. The supersonic air co-flow is preheated by burning a small amount of hydrogen in oxygen-enriched air. Stable numerical s...
Robust Estimation of UAV Dynamics in the Presence of Measurement Faults
Hacızade, Cengiz; Söken, Halil Ersin (American Society of Civil Engineers (ASCE), 2012-01-01)
This study introduces a robust Kalman filter (RKF) with a filter-gain correction for cases of measurement malfunctions. Using defined variables called measurement-noise scale factors, the faulty measurements are taken into consideration with a small weight and the estimations are corrected without affecting the characteristics of the accurate ones. In this study, RKF algorithms with single and multiple scale factors are proposed and applied for the state estimation process of an unmanned aerial vehicle (UAV...
Nontraditional Attitude Filtering with Simultaneous Process and Measurement Covariance Adaptation
Hacızade, Cengiz; Söken, Halil Ersin; Cilden-Guler, Demet (American Society of Civil Engineers (ASCE), 2019-09-01)
This study discusses simultaneous adaptation of the process and measurement noise covariance matrixes for a nontraditional attitude filtering algorithm. The nontraditional attitude filtering algorithm integrates the singular value decomposition (SVD) method with the unscented Kalman filter (UKF) to estimate the attitude of a nanosatellite. The SVD method uses magnetometer and Sun sensor measurements as the first stage of the algorithm and estimates the attitude of the nanosatellite, giving one estimate at a...
Estimation of pico-satellite attitude dynamics and external torques via Unscented Kalman Filter
Söken, Halil Ersin (FapUNIFESP (SciELO), 2014-01-01)
In this study, an Unscented Kalman Filter (UKF) algorithm is designed for estimating the attitude of a picosatellite and the in-orbit external disturbance torques. The estimation vector is formed by the satellite's attitude, angular rates, and the unknown constant components of the external disturbance torques acting on the satellite. The gravity gradient torque, residual magnetic moment, sun radiation pressure and aerodynamic drag are all included in the estimated external disturbance torque vector. The sa...
Citation Formats
F. M. Karadal, “Active flutter suppression of a smart fin,” M.S. - Master of Science, Middle East Technical University, 2008.