Experimental flutter boundaries with unsteady pressure distributionsfor the NACA 0012 Benchmark Model

Rivera, José A.; Dansberry, Bryan E.; Farmer, M. G.; Eckstrom, Clinton V.; Seidel, David A.; Bennett, Robert M.

doi:10.2514/6.1991-1010

Cited by 11 publications

(5 citation statements)

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“…Windtunnel test results of a NACA 0012 airfoil single-side mounted with two degree of freedom were published within the Benchmark Models Program at NASA Langley by Rivera et al (1991Rivera et al ( , 1992. A conventional flutter boundary showing a transonic dip, a plunge instability region and stall flutter was found.…”

Section: Introductionmentioning

confidence: 98%

“…Moreover, unsteady pressure measurements at the conventional flutter boundary were presented. One time-series of a combined heave and pitch motion exhibiting an LCO behavior at transonic flow conditions was shown (Rivera et al, 1991), but the amplitudes of the motion were not scaled. Edwards et al (2001) measured flutter boundaries and LCO behavior of a semi-span business jet wing-fuselage model MAVRIC-I.…”

Section: Introductionmentioning

confidence: 99%

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Experiments on heave/pitch limit-cycle oscillations of a supercritical airfoil close to the transonic dip

Dietz¹,

Schewe²,

Mai³

2004

Journal of Fluids and Structures

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Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Experiments on heave/pitch limit-cycle oscillations of a supercritical airfoil close to the transonic dip

Dietz¹,

Schewe²,

Mai³

2004

Journal of Fluids and Structures

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“…[1][2][3][4] These equations were developed analytically, using structural dynamic analysis and unsteady doublet lattice aerodynamics with rational polynomial approximations 5 . These linear state space equations consisted of 14 States (plunge, pitch, plunge rate, pitch rate, 3 aerodynamic states for plunge, 3 aerodynamic states for pitch, 2 trailing edge flap actuator states, 2 Dryden gust states), 2 inputs (actuator command and gust input noise) and 7 outputs (zte and zle acceleration, flap command, flap deflection, rate, acceleration, and gust velocity).…”

Section: Preliminary Analysismentioning

confidence: 99%

Transonic flutter suppression control law design using classical and optimal techniques with wind tunnel results

Mukhopadhyay

1999

40th Structures, Structural Dynamics, and Materials Conference and Exhibit

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The benchmark active controls technology and wind tunnel test program at NASA Langley Research Center was started with the objective to investigate the nonlinear, unsteady aerodynamics and active flutter suppression of wings in transonic flow. The paper will present the flutter suppression control law design process, numerical nonlinear simulation and wind tunnel test results for the NACA 0012 benchmark active control wing model. The flutter suppression control law design processes using (1) classical, (2) linear quadratic Gaussian (LQG), and (3) minimax techniques are described. A unified general formulation and solution for the LQG and minimax approaches, based on the steady state differential game theory is presented. Design considerations for improving the control law robustness and digital implementation are outlined. It was shown that simple control laws when properly designed based on physical principles, can suppress flutter with limited control power even in the presence of transonic shocks and flow separation. In wind tunnel tests in air and heavy gas medium, the closed-loop flutter dynamic pressure was increased to the tunnel upper limit of 200 psf. The control law robustness and performance predictions were verified in highly nonlinear flow conditions, gain and phase perturbations, and spoiler deployment. A non-design plunge instability condition was also successfully suppressed.

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“…The Structures Division of NASA Langley Research Center (LaRC) initiated the Benchmark Models Program (BMP) 1 . The goal of the BMP was to obtain experimental data for validating unsteady CFD codes.…”

Section: Introductionmentioning

confidence: 99%

The Benchmark Active Controls Technology model aerodynamic data

Scott

Hoadley

Wieseman

et al. 1997

35th Aerospace Sciences Meeting and Exhibit

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The Benchmark Active Controls Technology (BACT) model is a part of the Benchmark Models Program (BMP). The BMP is a NASA Langley Research Center program that includes a series of models which were used to study different aeroelastic phenomena and to validate computational fluid dynamics codes. The primary objective of BACT testing was to obtain steady and unsteady loads, accelerations, and aerodynamic pressures due to control surface activity in order to calibrate unsteady CFD codes and active control design tools. Three wind-tunnel tests in the Transonic Dynamics Tunnel (TDT) have been completed. The first and parts of the second and third tests focused on collecting open-loop data to define the model's aeroservoelastic characteristics, including the flutter boundary across the Mach range. It is this data that is being presented in this paper. An extensive database of over 3000 data sets was obtained. This database includes steady and unsteady control surface effectiveness data, including pressure distributions, control surface hinge moments, and overall model loads due to deflections of a trailing edge control surface and upper and lower surface spoilers. SYMBOLS

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Experimental flutter boundaries with unsteady pressure distributionsfor the NACA 0012 Benchmark Model

Cited by 11 publications

References 1 publication

Experiments on heave/pitch limit-cycle oscillations of a supercritical airfoil close to the transonic dip

Experiments on heave/pitch limit-cycle oscillations of a supercritical airfoil close to the transonic dip

Transonic flutter suppression control law design using classical and optimal techniques with wind tunnel results

The Benchmark Active Controls Technology model aerodynamic data

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