Nonlinear Flutter Analysis for the Scaled F-35 with Horizontal-Tail Free Play

Chen, P. C.; Ritz, Erich; Lindsley, Ned

doi:10.2514/1.c032501

Cited by 12 publications

(3 citation statements)

References 13 publications

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“…In addition, some studies showed that the free-play angle cannot be the only significant parameter involved in the free-play criteria (MIL-A-8870). Chen et al [24] presented the LCO characteristics of a scaled horizontal tail model with free-play and angle of attack. They found that in addition to the free-play angle, the angle of attack is also an important parameter affecting the LCO.…”

Section: Introductionmentioning

confidence: 99%

Experimental Aeroelastic Investigation of an All-Movable Horizontal Tail Model with Bending and Torsion Free-Plays

Bai

Qian

et al. 2023

Aerospace

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In this study, an experimental investigation is performed on a scaled, all-movable horizontal tail to study the aeroelastic behaviors induced by multiple free-plays. The dynamic response in wind tunnel tests is measured by strain gauges, an accelerometer, and a binocular vision measurement system. The obtained results indicate that the present aeroelastic system exhibits highly nonlinear characteristics and undergoes two independent limit cycle oscillations (LCOs) induced by bending free-play and torsion free-play, respectively. Further, various parametric studies are conducted to evaluate the effects of the free-play angles, angle of attack, flow velocity, and gust excitation on the LCOs. It is found that the value of free-play angle has no significant effect on the critical flow velocity which leads to the occurrence of LCOs. The amplitude and frequency of LCOs increase with the increasing free-play angle and flow velocity. Moreover, the horizontal tail experiences high-order harmonic resonances when LCOs appear. Finally, the stability of limit cycles is analyzed based on the gust excitation experiment. Overall, compared to an all-movable horizontal tail with single free-play, the multiple free-plays system exhibits more complex dynamic behaviors. In this paper, the measured results of the scaled model, which has a similar mass distribution and stiffness distribution as actual aircraft, may be valuable for predicting such LCOs induced by multiple free-plays, and providing a reference for the design of all-movable horizontal tail to prevent LCOs.

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Section: Introductionmentioning

confidence: 99%

Experimental Aeroelastic Investigation of an All-Movable Horizontal Tail Model with Bending and Torsion Free-Plays

Bai

Qian

et al. 2023

Aerospace

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show abstract

“…[1][2][3][4] Such nonlinearity can bring great impacts on handling quality, ride quality, and structural fatigue life. [5][6][7][8] Free-play has been recognized as a non-negligible inducement of these problems, because it is the most significant source of structural nonlinearity. [9][10][11][12] Various methods have been developed to study nonlinear aeroelastic behaviors induced by free-play.…”

Section: Introductionmentioning

confidence: 99%

Aeroelastic investigation on an all-movable horizontal tail with free-play nonlinearity

Ai,

Bai,

Qian

et al. 2023

Journal of Low Frequency Noise, Vibration and Active Control

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Free-play-induced nonlinear dynamic behavior has been one of the most important topics of aeroelastic research in recent decades. In this paper, the describing function (DF) method is developed to investigate the complex dynamic response of a popular all-movable horizontal tail with free-play. Piecewise expressions for the time history and phase portrait of limit cycle oscillation (LCO) are derived by the developed DF method, which is conducive to understand the mechanism of free-play-induced LCO. Another advantage of the developed DF method is the ability to predict the high-order harmonics, which cannot be realized by the classic DF method. A three-dimensional (3D) all-movable horizontal tail model with torsional free-play was designed and manufactured to implement wind tunnel tests via various initial parameters. A good agreement was found between the numerical and experimental results, which can demonstrate the effectiveness of the proposed method. The influence of the initial parameters of the all-movable horizontal tail on the LCO characteristics is analyzed by both numerical calculations and wind tunnel tests. The method and results in this paper can provide a significant reference for the design of all-movable horizontal tail versus the free-play-induced LCO.

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“…The study indicates the root rotation angle, gravity loads, and the initial conditions all significantly affect the LCO behavior. P.C Chen et al [5] performed a nonlinear flutter analysis to study the LCO characteristics of an F-35 windtunnel model with horizontal tail free-play effects using a direct simulation method. Fazil S et al [6] improved a multiobjective horizontal tail optimization approach by taking leading edge flap and trailing edge flaperon deflections into account.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Overall Cooling Effectiveness of Three-layer Laminate for Stealth Aircraft Tail Boom

Cao¹,

Ma²,

Liu³

et al. 2022

Proceedings of Global Power &Amp; Propulsion Society

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To study the cooling problem of stealth aircraft tail boom, which caused by the application of exhaust nozzle retraction technology. A Three-layer laminated cooling structure was established for tail boom. The overall cooling effectiveness and discharge coefficient of the structure were experimentally measured with different impingement distances (Hi/Dih=0.83,1.39) under blowing ratios (M=0.075~0.375), based on the infrared temperature measurement technology. The experimental results indicate that the laminated structure designed in this paper can efficiently cool the hot side wall of the tail boom for stealth aircraft. The area-averaged overall cooling effectiveness is 0.55~0.81 in the range of BR=0.075~0.375. The optimum blowing ratio is 0.300, and the corresponding area-averaged overall cooling effectiveness is above 0.8. The impingement distance has little effect on the overall cooling effectiveness. Hi/Dih increases from 0.83 to 1.39, the peak value of laterally averaged cooling effectiveness decreases, and the cooling uniformity of laminate surface is improved. Increasing the impingement distance will significantly reduce the flow resistance of this laminate. However, the flow resistance of three-layer laminate is still relatively large, Cd=0.098 for Hi/dfh=0.83 and Cd=0.132 for Hi/dfh=1.39. The flow resistance performance of this new structure needs to be studied to improve.

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Nonlinear Flutter Analysis for the Scaled F-35 with Horizontal-Tail Free Play

Cited by 12 publications

References 13 publications

Experimental Aeroelastic Investigation of an All-Movable Horizontal Tail Model with Bending and Torsion Free-Plays

Experimental Aeroelastic Investigation of an All-Movable Horizontal Tail Model with Bending and Torsion Free-Plays

Aeroelastic investigation on an all-movable horizontal tail with free-play nonlinearity

Experimental Study on Overall Cooling Effectiveness of Three-layer Laminate for Stealth Aircraft Tail Boom

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