Aircraft Design with Active Load Alleviation and Natural Laminar Flow

Jia, Xu; Kroo, Ilan

doi:10.2514/1.c032402

Cited by 65 publications

(20 citation statements)

References 46 publications

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“…Through maneuver and gust load alleviation technologies, the structure mass can be significantly decreased. For example, the NASA Sugar Volt design assumes that a properly designed active load alleviation system can reduce the wing weight by 25% [24].…”

Section: Active Load Alleviationmentioning

confidence: 99%

“…Preliminary studies [24][25][26][27][28] have shown that the application of flap systems for static gust and low dynamics maneuver load control has a potential to reduce takeoff mass and fuel consumption of long range transport aircraft. More aggressive load alleviation techniques and a wing planform designed to exploit these functions, as well as adapted thickness respectively, stiffness distributions are expected to increase the benefits to about a 25% reduction of the mass of the wing box, which can result in a 7% reduction of the fuel consumption [29].…”

Section: Active Load Alleviationmentioning

confidence: 99%

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Exploring Vehicle Level Benefits of Revolutionary Technology Progress via Aircraft Design and Optimization

et al. 2018

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Abstract:It is always a strong motivation for aeronautic researchers and engineers to reduce the aircraft emissions or even to achieve emission-free air transport. In this paper, the impacts of different game-changing technologies together on the reduction of aircraft fuel consumption and emissions are studied. In particular, a general tool has been developed for the technology assessment, integration and also for the overall aircraft multidisciplinary design optimization. The validity and robustness of the tool has been verified through comparative and sensitivity studies. The overall aircraft level technology assessment and optimization showed that promising fuel efficiency improvements are possible. Though, additional strategies are required to reach the aviation emission reduction goals for short and medium range configurations.

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Section: Active Load Alleviationmentioning

confidence: 99%

Section: Active Load Alleviationmentioning

confidence: 99%

Exploring Vehicle Level Benefits of Revolutionary Technology Progress via Aircraft Design and Optimization

et al. 2018

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“…The majority of research in this field employs inviscid-viscous coupling strategies, making use of boundary-layer codes for the viscous formulation and either a panel method or the Euler equations for the inviscid formulation. 30,31,32,33,34,35,36,37 Although the inviscid/viscous coupling strategies can be computationally cheaper than the higher-fidelity RANS solvers, the industry's trend toward the use of RANS solvers strongly suggests that NLF design tools should follow suit. Recent research making use of RANS solvers to optimize with transition prediction has shown promising results.…”

Section: Iib Rans-based Aerodynamic Shape Optimization For Nlfmentioning

confidence: 98%

Aerodynamic Shape Optimization for Natural Laminar Flow Using a Discrete-Adjoint Approach

Rashad

Zingg

2015

22nd AIAA Computational Fluid Dynamics Conference

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The design of natural-laminar-flow airfoils is demonstrated by high-fidelity, multipoint, aerodynamic shape optimization capable of efficiently incorporating and exploiting laminarturbulent transition. First, a two-dimensional Reynolds-averaged Navier-Stokes (RANS) flow solver has been extended to incorporate an iterative laminar-turbulent transition prediction methodology. The natural transition locations due to Tollmien-Schlichting instabilities are predicted using the simplified e N envelope method of Drela and Giles or alternatively, the compressible form of the Arnal-Habiballah-Delcourt criterion. The boundarylayer properties are obtained directly from the Navier-Stokes flow solution, and the transition to turbulent flow is modeled using an intermittency function in conjunction with the Spalart-Allmaras turbulence model. The RANS solver is subsequently employed in a gradient-based sequential quadratic programming shape optimization framework. The laminar-turbulent transition criteria are tightly coupled into the objective and gradient evaluations. The gradients are obtained using a new augmented discrete-adjoint formulation for non-local transition criteria. The aerodynamic design requirements are cast into a multipoint design optimization problem. A composite objective is defined using a weighted integral of the operating points. A Pareto front is also formed to study and quantify off-design performance. The proposed framework is applied to the single and multipoint optimization of subsonic and transonic airfoils, leading to robust natural-laminar-flow designs.

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“…Xu [2] also explores active-load-alleviation and its relationship to natural laminar flow. In this work, he found that active-load-alleviation could be used to reduce some of the structural penalties and thus create thinner wings with a higher aspect ratio.…”

Section: Introductionmentioning

confidence: 99%

Conceptualizing Active-Load-Alleviation: Impacts on Transport Category Aircraft Wing Structural Design

Allyn

Takahashi

2016

16th AIAA Aviation Technology, Integration, and Operations Conference

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This paper examines the structural effects of applying active-load-alleviation, through a symmetric negative incidence of the ailerons, to the detailed structural design of the torque box of a commercial aircraft. We will examine this effect across three different configurations, representing: 1) a regional jet (50,000-lbm), 2) a small narrow-body aircraft (100,000-lbm), and 3) a large narrow-body aircraft (150,000-lbm). We modelled the aerodynamic effects of active aileron reflex using a vortex lattice CFD code. Both baseline, elliptical, and reflexed aileron loads drove an iterative wing primary structure sizing tool that considers both the strength and the buckling stability of structure. We found that active-load-alleviation consistently leads to lighter structures through a reduction in bending moment. Because these structures are buckling rather than strength limited, we found that active-load-alleviation may not yield as much weight savings as its implied reduction in root bending moment might otherwise indicate. NomenclatureBL = Butt Line (ft) WL = Water Line (ft) α = Angle of Attack () CL = Coefficient of Lift t/c root = Thickness to Chord Ratio of Wing Section at the Root of the Wing (%) t/c tip = Thickness to Chord Ratio of Wing Section at the Tip of the Wing (%) b = Span of Wing (tip-to-tip) (ft) c = Chord of Wing (ft) TR = Taper Ratio (ratio of tip-chord to root-chord) Sref = Wing Planform Area (ft 2 ) MTOW = Maximum Takeoff Weight (lbm) MLW = Maximum Landing Weight (lbm) ±Nz = Load factor in the WL direction (g's)  ty = Material Tension Yield Strength (lbf/in 2 )  cy = Material Compressive Yield Strength (lbf/in 2 )  su = Material Ultimate Shear Strength (lbf/in 2 ) ρ = Material Density (lbf/in 3 ) E = Material Elastic Modulus (lbf/in 2 ) F.O.S. = Factor of Safety

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Aircraft Design with Active Load Alleviation and Natural Laminar Flow

Cited by 65 publications

References 46 publications

Exploring Vehicle Level Benefits of Revolutionary Technology Progress via Aircraft Design and Optimization

Exploring Vehicle Level Benefits of Revolutionary Technology Progress via Aircraft Design and Optimization

Aerodynamic Shape Optimization for Natural Laminar Flow Using a Discrete-Adjoint Approach

Conceptualizing Active-Load-Alleviation: Impacts on Transport Category Aircraft Wing Structural Design

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