scholarly journals Gust response and body freedom flutter of a flying-wing aircraft with a passive gust alleviation device

2017 ◽  
Vol 70 ◽  
pp. 277-285 ◽  
Author(s):  
S. Guo ◽  
Z.W. Jing ◽  
H. Li ◽  
W.T. Lei ◽  
Y.Y. He
Keyword(s):  
Gust Alleviation ◽  
Gust Response

Vibration behavior of an overhead conductor under updraft winds

2021 ◽  
pp. 107754632110058
Author(s):  
Qi Zhou ◽  
Liangtao Zhao ◽  
Chong Zheng ◽  
Feng Tu
Keyword(s):  
Induced Response ◽  
Response Analysis ◽  
Response Factor ◽  
Structural Dynamic ◽  
Resonance Response ◽  
Structural Dynamic Characteristics ◽  
Strong Winds ◽  
American Society ◽  
Gust Response Factor ◽  
Gust Response

At present, the wind-induced response analysis of an overhead conductor is mainly based on the action of horizontal normal wind. However, for crossing hillsides or extremely strong winds, such a conductor will bear the action of updraft wind, which will change the geometry of the conductor and make its structural dynamic characteristics nonlinear to some extent. In this work, the in-plane and out-of-plane two-dimensional nonlinear equations were established under the action of self-weight and updraft wind. Furthermore, the improved equations of conductor tension and sag were obtained, and the wind-induced vibration response was further investigated. The results showed that the updraft wind caused the nonlinearity of the tension and sag of the overhead conductor, and the nonlinear geometric change significantly affected its resonance response, which exceeded 25% if the wind speed was 50 m/s. In addition, because the proportion of the resonance response in the total wind-induced response was different, the influence of the wind attack angle calculated using the gust response factor method on the gust response factor was slightly larger than that calculated using the the American society of civil engineers method.

scholarly journals Gust Alleviation Control using Prior Gust Information: Wind Tunnel Test Results

2019 ◽  
Vol 52 (12) ◽  
pp. 128-133
Author(s):  
Yoshiro Hamada ◽  
Kenichi Saitoh ◽  
Noboru Kobiki
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Gust Alleviation

Analytical and experimental studies on the gust response of a 52 m tall steel lattice tower under wind loading

1999 ◽  
Vol 70 (2) ◽  
pp. 149-160 ◽  
Author(s):  
P. Harikrishna ◽  
J. Shanmugasundaram ◽  
S. Gomathinayagam ◽  
N. Lakshmanan
Keyword(s):  
Experimental Studies ◽  
Wind Loading ◽  
Lattice Tower ◽  
Gust Response

The Sears problem for a lifting airfoil revisited - new results

1984 ◽  
Vol 141 ◽  
pp. 109-122 ◽  
Author(s):  
H. M. Atassi
Keyword(s):  
Small Angle ◽  
Potential Flow ◽  
Angle Of Attack ◽  
Nonlinear Dependence ◽  
Mean Flow ◽  
Linear Superposition ◽  
Flow Angle ◽  
Independent Components ◽  
The Mean ◽  
Gust Response

It is shown that for a thin airfoil with small camber and small angle of attack moving in a periodic gust pattern, the unsteady lift caused by the gust can be constructed by linear superposition to the Sears lift of three independent components accounting separately for the effects of airfoil thickness, airfoil camber and non-zero angle of attack to the mean flow. This is true in spite of the nonlinear dependence of the unsteady flow on the mean potential flow of the airfoil. Specific lift formulas are derived and analysed to assess the importance of mean flow angle of attack and airfoil camber on the gust response.

scholarly journals Gust Mitigation of Micro Air Vehicles Using Passive Articulated Wings

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Adetunji Oduyela ◽  
Nathan Slegers
Keyword(s):  
Experimental Validation ◽  
Micro Air Vehicles ◽  
Flight Test ◽  
Analytical Investigation ◽  
Micro Air Vehicle ◽  
Gust Alleviation ◽  
Air Vehicle ◽  
Lifting Surfaces ◽  
Gust Mitigation ◽  
Air Vehicles

Birds and insects naturally use passive flexing of their wings to augment their stability in uncertain aerodynamic environments. In a similar manner, micro air vehicle designers have been investigating using wing articulation to take advantage of this phenomenon. The result is a class of articulated micro air vehicles where artificial passive joints are designed into the lifting surfaces. In order to analyze how passive articulation affects performance of micro air vehicles in gusty environments, an efficient 8 degree-of-freedom model is developed. Experimental validation of the proposed mathematical model was accomplished using flight test data of an articulated micro air vehicle obtained from a high resolution indoor tracking facility. Analytical investigation of the gust alleviation properties of the articulated micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes. Simulations show that passive articulation in micro air vehicles can increase their robustness to gusts within a range of joint compliance. It is also shown that if articulation joints are made too compliant that gust mitigation performance is degraded when compared to a rigid system.

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