Investigation on Characteristics of Nonlinear Aerodynamic System of Thin Plate Based on CFD Simulations
Abstract
In order to investigate the characteristics of nonlinear aerodynamic system of a thin plate, flow field around the thin plate under forced unit impulse excitation was simulated by the unsteady Reynolds-averaged Navier-Stokes (RANS) equations and SST k-ω turbulent model, and time histories of aerodynamic force were obtained. The nonlinear aerodynamic system of the thin plate was then identified based on the Volterra theory. The investigation indicates that the present aerodynamic model can provide reasonable output under the excitation within the defined ranges of frequency band and amplitude. Moreover, under the present range of forced frequency and amplitude, no clear dependence of model response on the frequency and amplitude is observed. It is also found that the aerodynamic nonlinearity of the thin plate is not significant, and the flow around the thin plate can be considered as an aerodynamic system with weak nonlinearity. This study confirms that the CFD method is of remarkable advantage for the identification of aerodynamic system of bridge girders.
Keywords: aerodynamic nonlinearity, thin plate, Volterra theory, CFD
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SCANLAN R H. TOMKO J J. Airfoil and bridge deck flutter derivatives [J]. Journal of Engineering Mechanics. ASCE. 1971. 97 (6):1171- 1737.
CHEN Z Q. YU X D. YANG G . et al. Wind-induced self-excited loads on bridges [J]. Journal of Structural Engineering. 2005. 131(12):1783 - 1793.
ZHU Z W. LES prediction of aerodynamics and coherence analysis of fluctuating pressure on box girders of long-span bridges [J]. Computers and Fluids. 2015. 110: 169 180.
ZHU Z W. GU M. CHEN Z Q. Wind tunnel and CFD study on identification of flutter derivatives of a long-span self-an-chored suspension bridge [J]. Computer-Aided Civil and Infrastructure Engineering. 2007. 22s541- 554.
ZHU Z W. GU M. Identification of flutter derivatives of bridge decks using CFI-based discrete-time aerodynamic models [J]. Wind and Structures. An International Journal. 2014. 18(3): 215-233.
VOLTERRA V. Theory of functionals and of integral and in-tegro-differential equations [J]. New York; Dover Pubns, 2005:63-105.
SILVA W A. Discrete-time linear and nonlinear aerodynamic impulse responses for efficient CFD analyses [D]. Williamsburg. Virginia:College of William &- Mary. 1997: 25 - 68.
MENTER F R. Two-equation eddy-viscosity turbulence models for engineering applications [J], A1AA Journal. 1994. 32 (8): 269 -289.
ZHU Zhiwen. XIA Chang. DENG Yanhua. Flow mechanisms around bluff rectangular cylinders and its principle component analysis [J]. Journal of ilunan University: Natural Science. 2012.39(7) :7- 13. (In Chinese)
ZHU Z W. CHEN Z Q. GU M. CFD based simulations of flutter characteristics of ideal thin plates with and without central slot [J]. Wind and Structures. 2009. 12(1) :1 - 19.
GU M. ZHANG R X. XIANG II F. Identification of flutter derivatives of bridge decks [J]. Journal of Wind Engineering and Industrial Aerodynamics. 2000. 84(2): 151-162.
ZHU Zhiwen. CHEN Zhengqing. GU Ming. Evaluating flutter derivatives of the thin plate by applying the numerical simulation method[J]. Journal of Hunan University; Natural Sci-ence.2005,32(5); 11- 15. (In Chinese)
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