scholarly journals Gust load alleviation wind tunnel tests of a large-aspect-ratio flexible wing with piezoelectric control

2017 ◽  
Vol 30 (1) ◽  
pp. 292-309 ◽  
Author(s):  
Ying Bi ◽  
Changchuan Xie ◽  
Chao An ◽  
Chao Yang
Keyword(s):  
Wind Tunnel ◽  
Aspect Ratio ◽  
Large Aspect Ratio ◽  
Wind Tunnel Tests ◽  
Flexible Wing ◽  
Piezoelectric Control ◽  
Gust Load Alleviation

An experimental parametric study on planar sheared wings tip devices for low-to-moderate aspect ratio wings

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lourelay Moreira dos Santos ◽  
Guilherme Ferreira Gomes ◽  
Rogerio F. Coimbra
Keyword(s):  
Wind Tunnel ◽  
Aspect Ratio ◽  
Parametric Study ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Sweep Angle ◽  
Wind Tunnel Tests ◽  
Content Type ◽  
Wing Tips ◽  
Wing Tip

Purpose The purpose of this study is to investigate the aerodynamic characteristics of a low-to-moderate-aspect-ratio, tapered, untwisted, unswept wing, equipped of sheared wing tips. Design/methodology/approach In this work, wind tunnel tests were made to study the influence in aerodynamic characteristics over a typical low-to-moderate-aspect-ratio wing of a general aviation aircraft, equipped with sheared – swept and tapered planar – wing tips. An experimental parametric study of different wing tips was tested. Variations in its leading and trailing edge sweep angle as well as variations in wing tip taper ratio were considered. Sheared wing tips modify the flow pattern in the outboard region of the wing producing a vortex flow at the wing tip leading edge, enhancing lift at high angles of attack. Findings The induced drag is responsible for nearly 50% of aircraft total drag and can be reduced through modifications to the wing tip. Some wing tip models present complex geometries and many of them present benefits in particular flight conditions. Results have demonstrated that sweeping the wing tip leading edge between 60 and 65 degrees offers an increment in wing aerodynamic efficiency, especially at high lift conditions. However, results have demonstrated that moderate wing tip taper ratio (0.50) has better aerodynamic benefits than highly tapered wing tips (from 0.25 to 0.15), even with little less wing tip leading edge sweep angle (from 57 to 62 degrees). The moderate wing tip taper ratio (0.50) offers more wing area and wing span than the wings with highly tapered wing tips, for the same aspect ratio wing. Originality/value Although many studies have been reported on the aerodynamics of wing tips, most of them presented complex non-planar geometries and were developed for cruise flight in high subsonic regime (low lift coefficient). In this work, an exploration and parametric study through wind tunnel tests were made, to evaluate the influence in aerodynamic characteristics of a low-to-moderate-aspect-ratio, tapered, untwisted, unswept wing, equipped of sheared wing tips (wing tips highly swept and tapered).

scholarly journals Fault Tolerant Control of an Experimental Flexible Wing

Aerospace ◽  
2019 ◽  
Vol 6 (7) ◽  
pp. 76
Author(s):  
Daniel Ossmann ◽  
Manuel Pusch
Keyword(s):  
Wind Tunnel ◽  
Filter Design ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Control Allocation ◽  
Detection Scheme ◽  
Single Input Single Output ◽  
Flexible Wing ◽  
Output Controller ◽  
Gust Load Alleviation

Active control techniques are a key factor in today’s aircraft developments to reduce structural loads and thereby enable highly efficient aircraft designs. Likewise, increasing the autonomy of aircraft systems aims to maintain the highest degree of operational performance also in fault scenarios. Motivated by these two aspects, this article describes the design and validation of a fault tolerant gust load alleviation control system on a flexible wing in a wind tunnel. The baseline gust load alleviation controller isolates and damps the weakly damped first wing bending mode. The mode isolation is performed via an H 2 -optimal blending of control inputs and measurement outputs, which allows for the design of a simple single-input single-output controller to actively damp the mode. To handle actuator faults, a control allocation scheme based on quadratic programming is implemented, which distributes the required control energy to the remaining available control surfaces. The control allocation is triggered in fault scenarios by a fault detection scheme developed to monitor the actuators using nullspace based filter design techniques. Finally, the fault tolerant control scheme is verified by wind tunnel experiments.

On-line analysis capabilities developed to support the active flexible wing wind-tunnel tests

1995 ◽  
Vol 32 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Carol D. Wieseman ◽  
Sherwood T. Hoadley ◽  
Sandra M. McGraw
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Tests ◽  
Flexible Wing ◽  
On Line ◽  
Line Analysis

scholarly journals Active Gust Load Alleviation of High-Aspect Ratio Flexible Wing Aircraft

2018 ◽  
Author(s):  
Yvonne Ferrier ◽  
Nhan T. Nguyen ◽  
Eric Ting ◽  
Daniel Chaparro ◽  
Xuerui Wang ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Flexible Wing ◽  
Gust Load Alleviation
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