scholarly journals A Novel Aerodynamic Force and Flutter of the High-Aspect-Ratio Cantilever Plate in Subsonic Flow

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Li Ma ◽  
Minghui Yao ◽  
Wei Zhang ◽  
Kai Lou ◽  
Dongxing Cao ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Subsonic Flow ◽  
Aerodynamic Force ◽  
Limit Cycle Oscillation ◽  
Cantilever Plate ◽  
Dynamical Equations ◽  
Ansys Fluent ◽  
Cycle Oscillation ◽  
Geometric Relationship

This paper focuses on the derivation of the aerodynamic force for the cantilever plate in subsonic flow. For the first time, a new analytical expression of the quasi-steady aerodynamic force related to the velocity and the deformation for the high-aspect-ratio cantilever plate in subsonic flow is derived by utilizing the subsonic thin airfoil theory and Kutta-Joukowski theory. Results show that aerodynamic force distribution obtained theoretically is consistent with that calculated by ANSYS FLUENT. Based on the first-order shear deformation and von Karman nonlinear geometric relationship, nonlinear partial differential dynamical equations of the high-aspect-ratio plate subjected to the aerodynamic force are established by using Hamilton’s principle. Galerkin approach is applied to discretize the governing equations to ordinary differential equations. Numerical simulation is utilized to investigate the relation between the critical flutter velocity and some parameters of the system. Results show that when the inflow velocity reaches the critical value, limit cycle oscillation occurs. The aspect ratio, the thickness, and the air damping have significant impact on the critical flutter velocity of the thin plate.

scholarly journals Bifurcation and dynamic behavior analysis of a rotating cantilever plate in subsonic airflow

2020 ◽  
Vol 41 (12) ◽  
pp. 1861-1880
Author(s):  
Li Ma ◽  
Minghui Yao ◽  
Wei Zhang ◽  
Dongxing Cao
Keyword(s):  
Aerodynamic Force ◽  
Shear Deformation Theory ◽  
Phase Portraits ◽  
Cantilever Plate ◽  
Dynamical Equations ◽  
Nonlinear Dynamical ◽  
Rotating Speed ◽  
Geometric Relationship ◽  
Asymptotic Perturbation ◽  
Nonlinear Geometric

AbstractTurbo-machineries, as key components, have a wide utilization in fields of civil, aerospace, and mechanical engineering. By calculating natural frequencies and dynamical deformations, we have explained the rationality of the series form for the aerodynamic force of the blade under the subsonic flow in our earlier studies. In this paper, the subsonic aerodynamic force obtained numerically is applied to the low pressure compressor blade with a low constant rotating speed. The blade is established as a pre-twist and presetting cantilever plate with a rectangular section under combined excitations, including the centrifugal force and the aerodynamic force. In view of the first-order shear deformation theory and von-Kármán nonlinear geometric relationship, the nonlinear partial differential dynamical equations for the warping cantilever blade are derived by Hamilton’s principle. The second-order ordinary differential equations are acquired by the Galerkin approach. With consideration of 1:3 internal resonance and 1/2 sub-harmonic resonance, the averaged equation is derived by the asymptotic perturbation methodology. Bifurcation diagrams, phase portraits, waveforms, and power spectrums are numerically obtained to analyze the effects of the first harmonic of the aerodynamic force on nonlinear dynamical responses of the structure.

scholarly journals Effect of Stiffness on Flutter of Composite Wings with High Aspect Ratio

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Shengjun Qiao ◽  
Jin Jiao ◽  
Yingge Ni ◽  
Han Chen ◽  
Xing Liu
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Limit Cycle Oscillation ◽  
Spanwise Direction ◽  
Aerodynamic Loads ◽  
Thin Walled Structures ◽  
Computational Fluid Dynamics Cfd ◽  
Cycle Oscillation

High aspect ratio wing (HARW) structures will deform greatly under aerodynamic loads, and changes in the stiffness will have a great impact on the flutter characteristics of such wings. Based on this, this paper presents an effective method to determine the effect of the stiffness on the flutter characteristics of HARWs. Based on the calculation theory of the mechanical profile of thin-walled structures, the torsional stiffness and bending stiffness of the wing are obtained through calculation. We use the fluid-structure coupling method to analyze the flutter characteristics of the wing, and we use our research results based on the corotational (CR) method to perform structural calculations. The load is calculated using a computational fluid dynamics (CFD) solver. The results show that, compared with the original wing, when the bending stiffness and torsional stiffness of the wing along the spanwise direction increase by 8.28% and 5.22%, respectively, the amplitude of the flutter decreases by approximately 30%. Increasing the stiffness in the range of 0.4 to 0.6 Mach has a greater impact on the flutter critical velocity, which increases by 12.03%. The greater the aircraft’s flight speed is, the more severe the stiffness affects the wing limit cycle oscillation (LCO) amplitude.

Limit-Cycle Oscillation of High-Aspect-Ratio Wings

2014 ◽  
Vol 556-562 ◽  
pp. 4329-4332
Author(s):  
Yan Ping Xiao ◽  
Yi Ren Yang ◽  
Peng Li
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Structural Equations ◽  
Limit Cycle Oscillation ◽  
Nonlinear Beam ◽  
Structural Nonlinearity ◽  
Cycle Oscillation

In this paper structural equations of motion based on nonlinear beam theory and the unsteady aerodynamic forces are gained to study the effects of geometric nonlinearity on the aerodynamic response of high-aspect-ratio wings. Then the Galerkin’s method is used to discretize the equations of motion. The results of HALE wing show good agreement with references. And other results investigate the effects of geometric structural nonlinearity on the response of a wing. Also the complex changes of the limit-cycle oscillation with speed increasing is carefully studied.

Effects of Aeroelastic Nonlinearity on Flutter and Limit Cycle Oscillations of High-Aspect-Ratio Wings

2011 ◽  
Vol 110-116 ◽  
pp. 4297-4306 ◽  
Author(s):  
Keivan Eskandary ◽  
Morteza Dardel ◽  
Mohammad Hadi Pashaei ◽  
Abdol Majid Kani
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Large Deflection ◽  
Limit Cycle Oscillation ◽  
Low Velocity ◽  
Wing Model ◽  
Structural Nonlinearities ◽  
Cycle Oscillation ◽  
Compressibility Effects

In this study aeroelastic characteristics of long high aspect ratio wing models with structural nonlinearities in quasi-steady aerodynamics flows are investigated. The studied wing model is a cantilever wing with double bending and torsional vibrations and with large deflection ability in according to Dowell-Hodges wing model. This wing model is valid for long, straight and thin homogeneous isotropic beams. Aerodynamics model is based on quasi-steady aerodynamic which is valid for aerodynamic flows in low velocity and without wake, viscosity and compressibility effects. The effect of different parameters such as mass ratios and stiffness ratios on flutter and divergence velocities and limit cycle oscillation amplitudes are carefully studied.

Limit cycle oscillation of a fluttering cantilever plate

AIAA Journal ◽  
1991 ◽  
Vol 29 (11) ◽  
pp. 1929-1936 ◽  
Author(s):  
Ye Weiliang ◽  
Earl Dowell
Keyword(s):  
Limit Cycle ◽  
Limit Cycle Oscillation ◽  
Cantilever Plate ◽  
Cycle Oscillation

Numerical Simulation of a High-Aspect-Ratio Wing Using High Fidelity Aero-Structural Coupled Method

2013 ◽  
Vol 465-466 ◽  
pp. 352-357
Author(s):  
Ze Hai Wang ◽  
Ming Yun Lv ◽  
Jun Hui Meng ◽  
Guo Quan Tao
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Aerodynamic Force ◽  
Geometrical Nonlinearity ◽  
High Fidelity ◽  
Coupled Method ◽  
Design And Optimization ◽  
Rigid Model ◽  
Inherent Nature ◽  
Drag Ratio

High-aspect-ratio wings, with the inherent nature of maximizing the lift-to-drag ratio, have been widely employed in modern airplanes. However, highly flexibility wing structure renders previous rigid model in aerodynamic simulation and ideal aerodynamic force distribution in structural simulation meet serious challenges. In this article, a high fidelity aero-structural coupled method is employed to better evaluating the deformation of a high-aspect-ratio wing. Summarily, this method takes into consideration the aerodynamic redistribution and the geometrical nonlinearity caused by large deformation of the wing, and the deflection calculated using coupled method is approximately 20% more than traditional unidirectional method, providing a more accurate model for structural design and optimization.

Nonlinear aeroelastic analysis of high-aspect-ratio wings in low subsonic flow

2012 ◽  
Vol 70 ◽  
pp. 6-22 ◽  
Author(s):  
K. Eskandary ◽  
M. Dardel ◽  
M.H. Pashaei ◽  
A.K. Moosavi
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Subsonic Flow ◽  
Aeroelastic Analysis

scholarly journals Bifurcation Analysis with Aerodynamic-Structure Uncertainties by the Nonintrusive PCE Method

2017 ◽  
Vol 2017 ◽  
pp. 1-17
Author(s):  
Linpeng Wang ◽  
Yuting Dai ◽  
Chao Yang
Keyword(s):  
Polynomial Chaos ◽  
Aerodynamic Force ◽  
Polynomial Chaos Expansion ◽  
Limit Cycle Oscillation ◽  
Structure Parameters ◽  
Chaos Expansion ◽  
Aeroelastic Model ◽  
Aerodynamic Parameters ◽  
Cycle Oscillation ◽  
The Time Domain

An aeroelastic model for airfoil with a third-order stiffness in both pitch and plunge degree of freedom (DOF) and the modified Leishman–Beddoes (LB) model were built and validated. The nonintrusive polynomial chaos expansion (PCE) based on tensor product is applied to quantify the uncertainty of aerodynamic and structure parameters on the aerodynamic force and aeroelastic behavior. The uncertain limit cycle oscillation (LCO) and bifurcation are simulated in the time domain with the stochastic PCE method. Bifurcation diagrams with uncertainties were quantified. The Monte Carlo simulation (MCS) is also applied for comparison. From the current work, it can be concluded that the nonintrusive polynomial chaos expansion can give an acceptable accuracy and have a much higher calculation efficiency than MCS. For aerodynamic model, uncertainties of aerodynamic parameters affect the aerodynamic force significantly at the stage from separation to stall at upstroke and at the stage from stall to reattach at return. For aeroelastic model, both uncertainties of aerodynamic parameters and structure parameters impact bifurcation position. Structure uncertainty of parameters is more sensitive for bifurcation. When the nonlinear stall flutter and bifurcation are concerned, more attention should be paid to the separation process of aerodynamics and parameters about pitch DOF in structure.

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