Characterization of the LCO Response Behaviors of the NATA model

An overview of recent progress regarding the computational aeroelastic and aeroservoelastic (ASE) analyses of a low-boom supersonic configuration is presented. The overview includes details of the computational models developed to date with a focus on unstructured CFD grids, computational aeroelastic analyses, sonic boom propagation studies that include static aeroelastic effects, and gust loads analyses. In addition, flutter boundaries using aeroelastic Reduced-Order Models (ROMs) are presented at various Mach numbers of interest. Details regarding a collaboration with the Royal Institute of Technology (KTH, Stockholm, Sweden) to design, fabricate, and test a full-span aeroelastic wind-tunnel model are also presented.

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Section: Kth Wind-tunnel Model and Testmentioning

confidence: 99%

A Status Review of the Commercial Supersonic Technology (CST) Aeroservoelasticity (ASE) Project

Silva

Sanetrik

Chwalowski

et al. 2016

34th AIAA Applied Aerodynamics Conference

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“…As indicated in previous section, even though the bicoherence and tricoherence enable us to define the presence of phase coupling when considering a single time series record [23,24], a more general approach is required when analyzing two or more time series records.…”

Section: B Frequency-domain Orthogonal Volterra Model Analysismentioning

confidence: 99%

Wind Tunnel Studies of Damaged-Wing-Induced Limit Cycle Oscillations

Park

Stearman

Kim

et al. 2008

Journal of Aircraft

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The influence of damage on the performance of the lifting surface of an aircraft has been an area of interest to the military for over half a century. Some of the earlier studies of this subject focused on the impact that structural damage resulting in the loss of lifting surface structural strength, stiffness, and mass might have on imparting catastrophic aeroelastic failures to the lifting surface. Discouraging mixed results arose over the next 30 years in these investigations that employed only structural damage models. As time passed, it was finally noticed that if the often neglected, usually second-order, drag term was now included (as aerodynamic damage often creates a high, unsteady, localized drag rise) in the earlier aeroelastic damaged-wing analyses, more encouraging results were obtained. That is, the realistic asymmetric damaged lifting surfaces flutter and divergence analysis did show lowered, and not raised, flutter and divergence speeds over that of the undamaged lifting surface. This occurred both in the presence of or in the absence of structural damage as in the case of icing or external wing stores. In essence, it was determined at this time that the resulting high and unsteady drag rise caused by the damage could do more than just cause an energy deficiency in the aircraft mission. It could, in fact, cause shorter term catastrophic or stiffness failure events in terms of reduced flutter and divergence speeds as well as give rise to limit cycle oscillations embedded within what was shown to be that part of the damaged-aircraft flight envelope free from classic flutter and divergence. The present experimental wind-tunnel study was carried out to confirm these past theoretical findings by employing a one-twelfth-scale F-111 aeroelastic model and (third-order) higher-order statistical signal processing to identify the frequency ordering that occurs in these additional damaged-induced limit cycle oscillations. These limit cycle oscillations were also found to exhibit the classic lock-in/lock-out phenomenon that occurs in the well-known F/A-16 and F/A-18 wing store induced limit cycle oscillations. Nomenclature C = modal damping matrix Ft = classical forcing function H C i; j; l = cubic frequency-domain Volterra transfer function H L k = linear frequency-domain Volterra transfer function H Q i; j = quadratic frequency-domain Volterra transfer function Kt = modal stiffness matrix which may vary with time M = modal mass matrix P C k = output of the cubic component of the Volterra model P L k = output of the linear component of the Volterra model P Q k = output of the quadratic component of the Volterra model P Y k = true observed response power spectrum PŶk = estimated response power spectrum of the Volterra model q = set of generalized coordinates S XX = power Spectrum of Xl S XXX = bispectrum of Xl S XXXX = trispectrum of Xl Xl = calculated value of the discrete Fourier transform of xn xn = nth sampled value of a digital time series Yl = calculated value of the discrete Fourier transform of yn yn= ...

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“…Although there is a significant amount of research being performed across several organizations in this area, a major limitation to this research is the availability of high-quality, transonic LCO data. [1][2][3][4][5][6][7][8][9][10][11][12] This paper presents the status of a collaborative effort between the Royal Institute of Technology (KTH) and the NASA Langley Research Center to acquire a high-quality LCO database on a full-span fighter configuration. The configuration selected will be discussed first, followed by a description of the computational aeroelastic analyses performed to date.…”

Section: Introductionmentioning

confidence: 99%

Computational Results for the KTH-NASA Wind-Tunnel Model Used for Acquisition of Transonic Nonlinear Aeroelastic Data

Silva

Chwalowski

Wieseman

et al. 2017

58th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

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A status report is provided on the collaboration between the Royal Institute of Technology (KTH) in Sweden and the NASA Langley Research Center regarding the aeroelastic analyses of a full-span fighter configuration wind-tunnel model. This wind-tunnel model was tested in the Transonic Dynamics Tunnel (TDT) in the summer of 2016. Large amounts of data were acquired including steady/unsteady pressures, accelerations, strains, and measured dynamic deformations. The aeroelastic analyses presented include linear aeroelastic analyses, CFD steady analyses, and analyses using CFD-based reduced-order models (ROMs).

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Characterization of the LCO Response Behaviors of the NATA model

Cited by 7 publications

References 9 publications

A Status Review of the Commercial Supersonic Technology (CST) Aeroservoelasticity (ASE) Project

A Status Review of the Commercial Supersonic Technology (CST) Aeroservoelasticity (ASE) Project

Wind Tunnel Studies of Damaged-Wing-Induced Limit Cycle Oscillations

Computational Results for the KTH-NASA Wind-Tunnel Model Used for Acquisition of Transonic Nonlinear Aeroelastic Data

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