NACA 0012 benchmark model experimental flutter results with unsteadypressure distributions

Rivera, José A.; Dansberry, Bryan E.; Bennett, Robert M.; Durham, Michael H.; Silva, Walter A.

doi:10.2514/6.1992-2396

Cited by 49 publications

(47 citation statements)

References 2 publications

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“…This region lies on the lower edge of the plunge instability region previously identified by Rivera et al [2]. This shedding region coincides with the range for which no wind-tunnel results were obtained.…”

Section: Discussionsupporting

confidence: 87%

Improved Flutter Boundary Prediction for an Isolated Two-Degree-of-Freedom Airfoil

Schwarz¹,

Dowell²,

Thomas³

et al. 2009

Journal of Aircraft

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A novel method of computing the flutter boundary for an isolated airfoil based on a high-fidelity computational fluid dynamics model reveals unusual behavior in a critical transonic range. Inviscid and viscous predictions of the flutter boundary for the two airfoils examined differ substantially in this critical region and become sensitive to Mach number and grid topology due to complicated shock/boundary-layer interactions. Computational fluid dynamics predictions of the flutter boundary for a NACA 0012 section airfoil are also compared with previous experimental results.

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Section: Discussionsupporting

confidence: 87%

Improved Flutter Boundary Prediction for an Isolated Two-Degree-of-Freedom Airfoil

Schwarz¹,

Dowell²,

Thomas³

et al. 2009

Journal of Aircraft

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“…Their computational flutter analysis showed good correlation with the experimental results of Rivera et al [2], except in the flow region near M 0:9. This disagreement was hypothesized to be due to the contributions of viscous effects.…”

supporting

confidence: 66%

“…Previous computational studies by Kholodar et al [1] tried to match the flutter boundary obtained experimentally by Rivera et al [2] in the Transonic Dynamics Tunnel at NASA Langley Research Center as part of the Benchmark Active Controls Technology (BACT) program [5]. This experiment used a three-dimensional wing model with a constant-chord NACA 0012 section.…”

Section: Comparison With Wind-tunnel Results For Benchmark Active mentioning

confidence: 99%

Improved Flutter Boundary Prediction for an Isolated Two-Degree-of-Freedom Airfoil

Schwarz¹,

Dowell²,

Thomas³

et al. 2008

49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference &Amp;lt;br> 16th AIAA/ASME/AHS Ada

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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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NACA 0012 benchmark model experimental flutter results with unsteadypressure distributions

Cited by 49 publications

References 2 publications

Improved Flutter Boundary Prediction for an Isolated Two-Degree-of-Freedom Airfoil

Improved Flutter Boundary Prediction for an Isolated Two-Degree-of-Freedom Airfoil

Improved Flutter Boundary Prediction for an Isolated Two-Degree-of-Freedom Airfoil

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

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