Recent Applications of Design Optimization to Rotorcraft-A Survey

Celi, Roberta

doi:10.2514/2.2424

Cited by 77 publications

(50 citation statements)

References 68 publications

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“…Spatial correlation matrix used in kriging R krg (·) Spatial correlation function in kriging r krg (x) Spatial correlation vector in kriging s 2 (x) Mean square error in kriging surrogate w Weight used in weighted expected improvement function t 1 , t 2 , t 3 Thicknesses of the blade cross-section, see Blade precone angle λ k Hover stability eigenvalue for k th mode ζ k , ω k…”

Section: Nomenclaturementioning

confidence: 99%

See 1 more Smart Citation

Efficient Global Optimization of Helicopter Rotor Blades for Vibration Reduction in Forward Flight

Glaz¹,

Friedmann²,

Liu³

2006

11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference

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The effectiveness of surrogate based optimization of helicopter rotor blades for vibration reduction using kriging global approximations is investigated. The search for the optimal design is conducted using two methods: (1) the "one-shot" approach in which the surrogate is optimized directly and (2) a method based on the expected improvement function which seeks to find optimal designs while reducing the uncertainty in the surrogate. The results indicate that the more global search based on the expected improvement function can lead to more optimal rotor blade designs with less function evaluations than the "one-shot" approach, and thus is more efficient. In addition, the results indicate that the application of parallel computation to the expected improvement function based method aids in finding more optimal blade designs even if the kriging approximations are not accurate everywhere in the design space. Nomenclature cBlade chordAssumed polynomials which account for the 'global' behavior in krigingMass polar moment of inertia of the rotor m 0Mass per unit length at the blade root m ns Non-structural mass located at the shear center

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Section: Nomenclaturementioning

confidence: 99%

“…The first approach is passive and uses structural/multidisciplinary optimization for reducing vibrations, [1][2][3][4] while the second approach utilizes active control methods. 5,6 This paper focuses on the passive approach.…”

Section: Introductionmentioning

confidence: 99%

Efficient Global Optimization of Helicopter Rotor Blades for Vibration Reduction in Forward Flight

Glaz¹,

Friedmann²,

Liu³

2006

11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference

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“…Although such methodologies have existed for decades, their use in preliminary design of rotorcraft has been rather limited, as pointed out by surveys such as [1,2].…”

Section: Introductionmentioning

confidence: 99%

Multiobjective Performance Optimization of a Coaxial Compound Rotorcraft Configuration

Hersey

Sridharan

Celi

2017

Journal of Aircraft

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This paper presents the results of a rotorcraft preliminary design problem, solved as a multiobjective design optimization problem. A lift-and thrust-augmented coaxial compound configuration is used to demonstrate the approach. The basic optimization problem is converted into a sequence of approximate optimization problems, in which approximate Pareto frontiers are calculated based on response surfaces, obtained from radial basis function interpolation of all the designs analyzed at every step of the sequence. The Pareto frontiers are computed using a genetic algorithm. The designs are analyzed using a high-fidelity rotorcraft analysis that includes nonlinear finite element models of the rotor blade and a free vortex wake model of the rotor inflow. The results presented indicate that 1) the preliminary design problem can be effectively solved using formal numerical design optimization techniques, which therefore can complement classical design methodologies; 2) with appropriate physics-based constraints, the design optimization can be carried out by the computer completely unattended; 3) the optimization methodology is sufficiently robust to deal with multiple local optima and other numerical difficulties; and 4) the methodology is efficient enough to allow the use of high-fidelity analyses throughout the optimization, with the use of graphical processing unit computing (Compute Unified Device Architecture/Fortran) contributing to the computational efficiency.Nomenclature F C X = objective function 2; power required in 220 kt cruise, hover power F H X = objective function 1; power required at hover, hover power N = number of design variables X = vector of design parameters x B ; y B ; z B = body-fixed axes (forward, starboard, and downward) α F = aerodynamic angle of attack of the fuselage (nose up), deg θ FW = root mounting angle of the wing (nose up), deg

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“…The first approach is passive and uses structural/multidisciplinary optimization for reducing vibrations. [1][2][3] The second approach utilizes active control methods. 4,5 The passive approach is used by blade designers to improve the vibration characteristics of the rotor.…”

Section: Introductionmentioning

confidence: 99%

Application of a Weighted Average Surrogate Approach to Helicopter Rotor Blade Vibration Reduction

Glaz

Goel

Liu

et al. 2007

48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

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The advantages of employing multiple approximation methods and the effectiveness of weighted average surrogate modeling for approximation and reduction of helicopter vibrations is studied. Multiple surrogates, including the weighted average approach, are considered so that the need to identify the "best" approximation method for the rotor vibration reduction problem is eliminated. Various approximation methods are used to generate a vibration objective function corresponding to a flight condition in which bladevortex interaction causes high levels of vibration. The design variables consist of the crosssectional dimensions of the structural member of the blade and non-structural masses. The optimized designs are compared with a baseline design resembling an MBB BO-105 blade. The results indicate that (a) multiple surrogates can be used to locate low vibration designs which would be overlooked if only a single approximation method was employed, and (b) that the weighted average approach protects against the worst individual surrogate, while performing as well as the best individual surrogate. Furthermore, the surrogates were used in a global sensitivity analysis to identify the most significant design variables for the vibration reduction problem.

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Recent Applications of Design Optimization to Rotorcraft-A Survey

Cited by 77 publications

References 68 publications

Efficient Global Optimization of Helicopter Rotor Blades for Vibration Reduction in Forward Flight

Efficient Global Optimization of Helicopter Rotor Blades for Vibration Reduction in Forward Flight

Multiobjective Performance Optimization of a Coaxial Compound Rotorcraft Configuration

Application of a Weighted Average Surrogate Approach to Helicopter Rotor Blade Vibration Reduction

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