A semi-empirical unsteady nonlinear aerodynamic model to predict transonic LCO characteristics of fighter aircraft

Meijer, J.J.; Cunningham, Maureen

doi:10.2514/6.1995-1340

Cited by 23 publications

(3 citation statements)

References 6 publications

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“…In addition, many instances of LCO occur in the highly nonlinear transonic regime. Early efforts to develop a suitable aerodynamic analysis tool relied extensively on semi-empirical methods [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Investigation of Missile Control Surface Effects on F-16 Limit-Cycle Oscillation

Hanson

Kunz

Lindsley

2015

Journal of Aircraft

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Tactical aircraft with thin wings and heavy external wing stores are susceptible to aeroelastic limit-cycle oscillations. This investigation applies both frequency-domain and time-domain solutions using aeroelastic computational models to predict limit-cycle oscillation onset, frequency, and amplitude on an F-16. The test configuration uses missile shapes with reconfigurable aerodynamic and mass properties. Statistical analysis of flighttest results identifies significant experimental variables of missile aerodynamic configuration, flight condition, and aircraft fuel state. Furthermore, statistical analysis permits the normalization of flight-test results for direct comparison to aeroelastic models. Results of the comparison show that flight-test data analysis mostly supports the prediction trends, but the magnitude of the aerodynamic effects due to the canards and fins is much less significant in the test data.

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Section: Introductionmentioning

confidence: 99%

Investigation of Missile Control Surface Effects on F-16 Limit-Cycle Oscillation

Hanson

Kunz

Lindsley

2015

Journal of Aircraft

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“…A common approach has been to estimate a model based purely on measured responses using system identi"cation algorithms; however, these approaches typically have di$culties estimating low damped modes or lag terms associated with unsteady aerodynamics. A similar approach has been formulated that has shown success for predicting LCO [6]. This approach noted characteristics from wind tunnel measurements and identi"ed model properties to match those characteristics [7].…”

Section: Introductionmentioning

confidence: 99%

Wavelet Analysis to Characterise Non-Linearities and Predict Limit Cycles of an Aeroelastic System

Lind

Snyder

Brenner

2001

Mechanical Systems and Signal Processing

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“…This aerodynamic phenomenon can cause a nonlinear relationship between the structural motion and the aerodynamic pressure acting on the structure. Cunningham and Meijer [12] and Meijer and Cunningham [13] have shown that nonlinear aerodynamic forces originated by shock induced trailing edge separation can be a dominant mechanism in the LCO. Detailed discussions of these aerodynamic nonlinearities issues are available, for instance, in [14,15,16].…”

Section: Literature Reviewmentioning

confidence: 99%

Nonlinear Aeroelastic Modeling of a Flexible Wing and Comparison with Experiments

Costa¹

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A wind tunnel experimental investigation of limit cycle oscillations (LCO) of a uniform flexible airfoil with root pitch motion occurring at transitional Reynolds number regime (4.5×10 4 ≤ Re c ≤ 1.3 × 10 5 ) is presented. Depending on the initial conditions, two stable limit cycle regimes are observed: small and large amplitude LCO. The origin of the large amplitude LCO is determined to be coalescence flutter for which the exponential growth of the amplitude is limited by the stall at large angles of attack. On the other hand, the small amplitude LCO are attributed to laminar boundary layer separation related to transitional Reynolds number aerodynamics. In addition, the nonlinear equations of motion for a cantilever is developed considering chordwise and flapwise bending, torsion and base rotation. The nonlinearities arise from two main sources: the structural flexibility and the coupling of the bending and torsional motions with the base rotation. Furthermore, a linear inviscid aerodynamic model is considered using both quasisteady and unsteady forcing terms. Despite the linear aerodynamics approximations, a parallel to the experiments can be drawn with the numerical simulations presented for small and large amplitude LCO at the vicinity of the linear flutter speed, with a dominant cause factor being a coalescence flutter.Overall, the structural nonlinearities play significant role in LCO for both the experimental and numerical investigations.ii

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A semi-empirical unsteady nonlinear aerodynamic model to predict transonic LCO characteristics of fighter aircraft

Cited by 23 publications

References 6 publications

Investigation of Missile Control Surface Effects on F-16 Limit-Cycle Oscillation

Investigation of Missile Control Surface Effects on F-16 Limit-Cycle Oscillation

Wavelet Analysis to Characterise Non-Linearities and Predict Limit Cycles of an Aeroelastic System

Nonlinear Aeroelastic Modeling of a Flexible Wing and Comparison with Experiments

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