Application of Active Aeroelastic Wing Technology to a Joined-Wing Sensorcraft

Reich, Gregory W.; Raveh, Daniella E.; Zink, P. Scott

doi:10.2514/6.2002-1633

Cited by 15 publications

(8 citation statements)

References 6 publications

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“…A separate deflection pattern may be optimized for each trim load case, where the distributed control surfaces would simultaneously alleviate the loads into the wing structure and help maintain aerodynamic trim. This may be done by solving an over-determined trim problem, where flap deflection scheduling is optimized such that trim is maintained (posed as a constraint) and some objective of interest is minimized: root bending moment [3], deformations at given finite element nodes [4], drag, etc. This typically is posed as a nested optimization solution, where structural design variables are applied to the over-determined trim solution.…”

Section: Introductionmentioning

confidence: 99%

Optimization of an Aeroservoelastic Wing with Distributed Multiple Control Surfaces

Stanford

2015

33rd AIAA Applied Aerodynamics Conference

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This paper considers the aeroelastic optimization of a subsonic transport wingbox under a variety of static and dynamic aeroelastic constraints. Three types of design variables are utilized: structural variables (skin thickness, stiffener details), the quasi-steady deflection scheduling of a series of control surfaces distributed along the trailing edge for maneuver load alleviation and trim attainment, and the design details of an LQR controller, which commands oscillatory hinge moments into those same control surfaces. Optimization problems are solved where a closed loop flutter constraint is forced to satisfy the required flight margin, and mass reduction benefits are realized by relaxing the open loop flutter requirements.

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Section: Introductionmentioning

confidence: 99%

Optimization of an Aeroservoelastic Wing with Distributed Multiple Control Surfaces

Stanford

2015

33rd AIAA Applied Aerodynamics Conference

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“…This is done by altering the external airloads on the wing rather than the internal stiffness, but these divisions are blurred in any case due to the coupled aeroelastic nature of the system. The flap deflection scheduling can be optimized such that trim is maintained (constraint) and some objective of interest is minimized: root bending moment [13], deformations at given finite element nodes [14], drag, etc. Alternatively, structural design variables may be optimized concurrently with the control surface scheduling [15], either iteratively or simultaneously.…”

Section: Introductionmentioning

confidence: 99%

Trim and Structural Optimization of Subsonic Transport Wings Using Nonconventional Aeroelastic Tailoring

2016

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Several minimum-mass aeroelastic optimization problems are solved to evaluate the effectiveness of a variety of novel tailoring schemes for subsonic transport wings. Aeroelastic strength and panel buckling constraints are imposed across a variety of trimmed maneuver loads. Tailoring with metallic thickness variations, functionally graded materials, composite laminates, tow steering, and distributed trailing edge control effectors are all found to provide reductions in structural wing mass with varying degrees of success. The question as to whether this wing mass reduction will offset the increased manufacturing cost is left unresolved for each case.

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“…This current investigation is focused on the effectiveness of gust alleviation by a specially-designed passive twist wingtip (PTWT). This particular PTWT has been studied in previous research for large unmanned air vehicles, including a flying wing aircraft [6,7] and jointed-wing sensor craft [8][9][10][11][12] of very flexible and high aspect ratio wings. The results have shown that the gust load has been significantly reduced by employing such a passive gust load alleviation device with optimized design parameters.…”

Section: Introductionmentioning

confidence: 99%

Gust Alleviation of a Large Aircraft with a Passive Twist Wingtip

2015

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This paper presents an investigation into the gust response and wing structure load alleviation of a 200-seater aircraft by employing a passive twist wingtip (PTWT). The research was divided into three stages. The first stage was the design and analysis of the baseline aircraft, including aerodynamic analysis, structural design using the finite element (FE) method and flutter analysis to meet the design requirements. Dynamic response analysis of the aircraft to discrete (one-cosin) gust was also performed in a range of gust radiances specified in the airworthiness standards. In the second stage, a PTWT of a length of 1.13 m was designed with the key parameters determined based on design constraints and, in particular, the aeroelastic stability and gust response. Subsequent gust response analysis was performed to evaluate the effectiveness of the PTWT for gust alleviation. The results show that the PTWT produced a significant reduction of gust-induced wingtip deflection by 21% and the bending moment at the wing root by 14% in the most critical flight case. In the third stage, effort was made to study the interaction and influence of the PTWT on the symmetric and unsymmetrical manoeuvring of the aircraft when ailerons were in operation. The results show the that PTWT influence with a reduction of the aircraft normal velocity and heave motion by 1.7% and 3%, respectively, is negligible. However, the PTWT influence on the aircraft roll moment with a 20.5% reduction is significant. A locking system is therefore required in such a manoeuvring condition. The investigation has shown that the PTWT is an effective means for gust alleviation and, therefore, has potential for large aircraft application.

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Application of Active Aeroelastic Wing Technology to a Joined-Wing Sensorcraft

Cited by 15 publications

References 6 publications

Optimization of an Aeroservoelastic Wing with Distributed Multiple Control Surfaces

Optimization of an Aeroservoelastic Wing with Distributed Multiple Control Surfaces

Trim and Structural Optimization of Subsonic Transport Wings Using Nonconventional Aeroelastic Tailoring

Gust Alleviation of a Large Aircraft with a Passive Twist Wingtip

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