VIBRATION AND TRANSONIC FLUTTER ANALYSIS FOR F-16 STORES CONFIGURATION CLEARANCE

2006 ◽  
Vol 06 (03) ◽  
pp. 377-395 ◽  
Author(s):  
ROBERT A. CANFIELD ◽  
RAYMOND G. TOTH ◽  
REID MELVILLE
Keyword(s):  
Frequency Tuning ◽  
Ground Vibration ◽  
Element Model ◽  
Limit Cycle Oscillation ◽  
Flight Tests ◽  
Flutter Speed ◽  
Flutter Analysis ◽  
Transonic Flutter ◽  
Cycle Oscillation ◽  
Nonlinear Aerodynamic

This paper supports quick and accurate prediction of the flutter onset speed of an F-16 Block 40/50 configured with external stores in the transonic flight regime. Current flutter prediction methods are reviewed and hypothesized mechanisms for limit cycle oscillation (LCO) are summarized. New efforts to correlate transonic small disturbance (TSD) theory methods with flight tests are outlined. Vibration analysis and structural optimization of an F-16 finite element model were used to match ground vibration testing results. Frequency tuning was found to be critical for accurate flutter speed predictions. Sensitivity to nonlinear aerodynamic effects and store modeling was examined.

Static/Dynamic Edge Movability Effect on Non-Linear Aerothermoelastic Behavior of Geometrically Imperfect Curved Skin Panel: Flutter and Post-Flutter Analysis

2012 ◽  
Vol 79 (4) ◽  
Author(s):  
Laith K. Abbas ◽  
Xiaoting Rui ◽  
P. Marzocca ◽  
M. Abdalla ◽  
R. De Breuker
Keyword(s):  
Stable Limit Cycle ◽  
Limit Cycle Oscillation ◽  
Stable Limit ◽  
Third Order ◽  
Curved Panel ◽  
Flutter Analysis ◽  
Non Linear ◽  
Cycle Oscillation ◽  
Modeling Behavior ◽  
Curved Panels

This paper addresses the problem of the aerothermoelastic modeling behavior and analyses of skin curved panels with static and dynamic edge movability effect in high supersonic flow. Flutter and post-flutter behavior will be analyzed toward determining under which conditions such panels will exhibit a benign instability, that is a stable limit cycle oscillation, or a catastrophic instability, that is an unstable LCO. The aerothermoelastic governing equations are developed from the geometrically non-linear theory of infinitely long two dimensional curved panels. Von Kármán non-linear strain-displacement relation in conjunction with the Kirchhoff plate-hypothesis is adopted. A geometrically imperfect curved panel forced by a supersonic/hypersonic unsteady flow is numerically investigated using Galerkin approach. These equations are based on the third-order piston theory aerodynamic for modeling the flow-induced forces. Furthermore, the effects of thermal degradation and Kelvin’s model of structural damping independent of time and temperature are also considered in this model. Computational analysis and discussion of the finding along with pertinent conclusions are presented.

Limit-cycle oscillation induced by nonlinear aerodynamic forces

AIAA Journal ◽  
2002 ◽  
Vol 40 ◽  
pp. 2197-2205
Author(s):  
K. W. Dotson ◽  
R. L. Baker ◽  
B. H. Sako
Keyword(s):  
Limit Cycle ◽  
Limit Cycle Oscillation ◽  
Aerodynamic Forces ◽  
Cycle Oscillation ◽  
Nonlinear Aerodynamic

Limit-Cycle Oscillation Induced by Nonlinear Aerodynamic Forces

AIAA Journal ◽  
2002 ◽  
Vol 40 (11) ◽  
pp. 2197-2205 ◽  
Author(s):  
K. W. Dotson ◽  
R. L. Baker ◽  
B. H. Sako
Keyword(s):  
Limit Cycle ◽  
Limit Cycle Oscillation ◽  
Aerodynamic Forces ◽  
Cycle Oscillation ◽  
Nonlinear Aerodynamic

A Characterization of Limit Cycle Oscillations in Membrane Wing Micro Air Vehicles at Low Angle of Attack

2010 ◽  
Author(s):  
Peter J. Attar ◽  
Jordan W. Johnston ◽  
William A. Romberg ◽  
Ramkumar N. Parthasarathy ◽  
Brian J. Morris
Keyword(s):  
Limit Cycle ◽  
Micro Air Vehicles ◽  
Element Model ◽  
Limit Cycle Oscillation ◽  
Limit Cycle Oscillations ◽  
Wing Membrane ◽  
Membrane Wing ◽  
Cycle Oscillation ◽  
Nonlinear Finite Element Model ◽  
Air Vehicles

In this paper, a (three) batten-reinforced fixed wing membrane micro air vehicle is used to determine the effect of membrane pre-strain on flutter and limit cycle behavior of fixed wing membrane Micro Air Vehicles. For each configuration tested, flutter and subsequent limit cycle oscillations are measured in wind tunnel tests and predicted using an aeroelastic computational model consisting of a nonlinear finite element model coupled to a vortex lattice solution of the Laplace equation and boundary conditions. Agreement between the predicted and measured onset of limit cycle oscillation is good as is the prediction of the amplitude of the limit cycle at the trailing edge of the lower membrane. A direct correlation between levels of strain and the phase of the membranes during the limit cycle is found in the computation and thought to also occur in the experiment.

Flutter Analysis of X-HALE UAV-A Test Bed for Aeroelastic Results Validation

2012 ◽  
Vol 245 ◽  
pp. 303-309
Author(s):  
Kamran Ahmad ◽  
Hammad Rahman
Keyword(s):  
Structural Deformation ◽  
Strain Gauges ◽  
Limit Cycle Oscillation ◽  
Test Bed ◽  
Nonlinear Analyses ◽  
Structural Forces ◽  
Aeroelastic Analysis ◽  
Flutter Analysis ◽  
Cycle Oscillation ◽  
Wing Deformation

Aeroelasticity is one of the important fields in design of an aircraft or a flying vehicle. It deals with the interaction of aerodynamic, inertial and structural forces. The interaction between these different forces leads to certain aeroelastic phenomena such as divergence, flutter and limit cycle oscillation. Linear aeroelastic analyses of high aspect ratio wings act as basis for nonlinear analysis. Because of large wing deformation nonlinear analyses has to be performed for correct modeling. X-HALE UAV is a test bed exhibiting large structural deformation. Equipped with strain gauges and other measuring sensors, it will provide experimental data which can then be used for nonlinear aeroelastic analyses for other such kind of structures. This papers deals with the linear aeroelastic analysis of this type of aircraft.

Synthetic Design of High Aspect Ratio Folding Wings Based on Aeroelastic Analysis

2014 ◽  
Vol 607 ◽  
pp. 409-412
Author(s):  
Sheng Li Lv ◽  
Cheng Wang ◽  
Yang Biao Ou ◽  
Guang Jun Yang ◽  
Xiao Yan Tong
Keyword(s):  
Engineering Application ◽  
Element Model ◽  
Expansion Process ◽  
Sweep Angle ◽  
Flutter Speed ◽  
Aeroelastic Analysis ◽  
Flutter Analysis ◽  
Practical Engineering ◽  
Analysis Models ◽  
Relationship Of

Finite element model of folding wings was designed in the light of structural scheme, and each part of the model used composites. Different aeroelastic analysis models were built from emission to cruise, and then the models were made the study focus on flutter analysis. The result showed the change relationship of the critical flutter speed of wings and flutter frequency with sweep angle in state of expansion process, and the change relationship of the critical flutter speed of wings and flutter frequency of folding wings with cruising altitude and cruise Mach number in state of cruise. The whole flight state was analyzed if the folding wings might flutter, and if it took place the structure optimization of wings was needed. Simulation results have a certain guiding significance for practical engineering application.

scholarly journals Experimental Investigation on a Novel Airfoil-Based Piezoelectric Energy Harvester for Aeroelastic Vibration

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 725
Author(s):  
Xiaobiao Shan ◽  
Haigang Tian ◽  
Han Cao ◽  
Ju Feng ◽  
Tao Xie
Keyword(s):  
Nonlinear Response ◽  
Energy Harvester ◽  
Limit Cycle Oscillation ◽  
Airflow Velocity ◽  
Lower Velocity ◽  
Output Performance ◽  
Piezoelectric Energy ◽  
Cycle Oscillation ◽  
Two Degree Of Freedom ◽  
Nonlinear Aerodynamic

This paper presents a novel airfoil-based piezoelectric energy harvester (EH) with two small square prisms attached to an airfoil. This harvester can achieve a two degree-of-freedom (DOF) plunge–pitch motions. Several prototypes of energy harvester were fabricated to explore the nonlinear aerodynamic response and the output performance in a wind tunnel. The experimental results showed that the longer the flexible spring was, the lower the critical velocity and frequency of the harvester were, and the better aerodynamic response and output performance could be achieved. The initial disturbance, the following limit-cycle oscillation, and the ultimate chaos of nonlinear response occurred, as increasing airflow velocity was increased. The overall output performance of the harvesters with a flexible spring having a thickness of 1 mm outperformed than that of the harvesters with a flexible spring having a thickness of 0.5 mm at a higher airflow velocity, while the tendency was opposite at a lower velocity. An optimum output voltage of 17.48 V and a power of 0.764 mW were harvested for EH-160-1 at 16.32 m/s, which demonstrated it possessed better performance than the other harvesters. When the capacitor was charged for 45 s and directly drove a sensor, it could maintain working for 17 s to display temperature and humidity in real time.

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