ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2026 · January 1, 2026
Aeroelastic flutter onset and limit cycle oscillation results are computed for a two-dimensional model of the NASA benchmark supercritical wing configuration consisting of the NASA SC(2)0414 airfoil section. The purpose of this investigation is to contribu ...
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ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2026 · January 1, 2026
Transonic flow over a NACA0012 airfoil is simulated using Unsteady Reynolds-averaged Navier-Stokes (URANS) in Ansys Fluent to study the interaction of wall geometry and Mach number on the prediction of transonic buffet onset and offset. The wall boundaries ...
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ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2026 · January 1, 2026
Numerical simulation of the transonic shock buffet phenomenon remains a formidable challenge due to its inherent nonlinear and unsteady characteristics. These difficulties are further compounded in three-dimensional configurations and when aeroelastic coup ...
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ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2026 · January 1, 2026
This work investigates the aeroelastic response of a Clamped-Free-Clamped-Free (CFCF) compliant panel subjected to hypersonic flow, with emphasis on understanding the flow physics governing the behavior of the aeroelastic response. Inviscid flow models suc ...
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ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2026 · January 1, 2026
The dynamically linearized time-domain approach (DLTA) reduced order model (ROM) is expanded to include large deformation effects into the aeroelastic solution of cantilevered structures. This correction is used to compute the generalized aerodynamic force ...
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ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2025 · January 1, 2025
Aeroelastic limit cycle oscillation results are presented for a three-degree-of-freedom plunge, pitch, and flap structural model with flap free-play in a viscous transonic flow airfoil. A nonlinear frequency domain harmonic balance approach is used for the ...
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ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2025 · January 1, 2025
This paper investigates the flutter mechanism of the benchmark supercritical wing at Mach 0.8 with the angle-of-attack (AOA) at 1◦, 3◦ and 5◦. Nonlinear unsteady aerodynamic reduced order models (ROMs) are used which are tr ...
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ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2025 · January 1, 2025
A nonlinear aeroelastic model for a flexible panel is expanded to consider the effect of the viscous boundary layer using a RANS solver. This study presents the use of a Reduced Order Model (ROM) to compute the generalized aerodynamic force from a CFD simu ...
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ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2025 · January 1, 2025
This study investigates clamped-free-clamped-free (CFCF) compliant aluminum alloy panels under hypersonic flow conditions. The goal is to enhance the understanding of Fluid-Structure Interaction (FSI) by computationally simulating approximate experimental ...
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ConferenceAIAA Aviation Forum and Ascend 2025 · January 1, 2025
A computational nonlinear aeroelastic solver was used in combination with the Dynamically Linearized Time-domain Approach (DLTA) Reduced Order Model (ROM) to correlate results with the AFRL RC-9 supersonic wind tunnel measurement campaign. This study is pa ...
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ConferenceAIAA Scitech Forum and Exposition 2024 · January 1, 2024
The application of a nonlinear aeroelastic model for a flexible panel is expanded to consider the Euler equation as the aerodynamic model. This study presents the method to compute the generalized aerodynamic force from a CFD simulation and compares the re ...
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ConferenceAIAA Scitech Forum and Exposition 2024 · January 1, 2024
Wall-modeled large eddy simulation (WMLES) and a theoretical-computational aeroelastic solver are used to predict the motion of a thin flexible panel under an impinging shock wave. Panel displacements imposed by the resulting shock-wave/boundary-layer inte ...
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ConferenceAIAA Scitech Forum and Exposition 2024 · January 1, 2024
The unsteady pressure distribution over a NACA 0012 air foil is measured in a low-speed wind tunnel for a rigid airfoil and control surface configuration. The experimental protocol is to give a step change in the airfoil angle of attack and the control sur ...
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ConferenceAIAA Scitech Forum and Exposition 2024 · January 1, 2024
In this study, we apply computational fluid dynamics (CFD) to compare transonic buffet over several airfoil geometries and flow conditions. Transonic buffet is a fluid instability in which a recompression shock oscillates over the upper surface of an airfo ...
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ConferenceAIAA Aviation Forum and Ascend 2024 · January 1, 2024
An approach to incorporate the motion of a flexible panel under an impinging shockwave/ boundary-layer interaction (SBLI) at Mach 2.5 into a wall-modeled large eddy simulation (WMLES) is developed and implemented. The panel oscillations predicted by an aer ...
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ConferenceIcas Proceedings · January 1, 2024
For high-speed vehicles, shock waves are inevitably encountered when traveling at supersonic speeds, which creates challenges in their design and operation. The consequent severe pressure and thermal loads aggravate the aeroelastic response, threatening st ...
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ConferenceInternational Forum on Aeroelasticity and Structural Dynamics Ifasd 2024 · January 1, 2024
In this study, a novel dynamically linearized Euler time-domain approach is used to compute the generalized aerodynamic force from a CFD simulation. The aerodynamic forcing term is implemented in a theoretical/computational nonlinear aeroelastic model to a ...
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ConferenceInternational Forum on Aeroelasticity and Structural Dynamics Ifasd 2024 · January 1, 2024
Fluid structure interaction of an elastic plate with piezoelectric elements, turbulent freestream flow at Mach 2.5, and a pressurized cavity is investigated computationally and correlated with a recent experiment. The pressure field on the surface of the p ...
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ConferenceAIAA Scitech Forum and Exposition 2023 · January 1, 2023
This study applies computational fluid dynamics (CFD) to transonic buffet, a flow field instability characterized by an oscillating shock on the upper surface of an airfoil in transonic flow. Despite years of research in this area, understanding of the und ...
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ConferenceAIAA Scitech Forum and Exposition 2023 · January 1, 2023
Presented is a technique that significantly improves the computational performance of an existing harmonic balance-based flutter onset and limit-cycle oscillation aeroelastic solution methodology. The existing harmonic balance aeroelastic solution methodol ...
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ConferenceAIAA Scitech Forum and Exposition 2023 · January 1, 2023
The Potential Aerodynamic Theory is implemented to model the flow over a flexible panel. The present study compares the more complete unsteady version of the potential flow theory with its simplification known as the Linear Piston Theory for different Mach ...
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ConferenceAIAA Science and Technology Forum and Exposition AIAA Scitech Forum 2022 · January 1, 2022
A methodology for leveraging a combination of linear (through convolution integrals) and nonlinear (through Volterra series) reduced-order modeling (ROM) development was demonstrated on both a 2 and 3 degree of freedom (DOF) aeroelastic system. The linear/ ...
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ConferenceAIAA Aviation 2022 Forum · January 1, 2022
Presented is a point collocation non-intrusive polynomial chaos approach for nonlinear aeroelastic uncertainty quantification analysis. A unique aspect of our approach is that we are using a nonlinear frequency-domain harmonic balance aeroelastic solution ...
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ConferenceProceedings of the International Forum of Aeroelasticity and Structural Dynamics 2022 Ifasd 2022 · January 1, 2022
A cantilevered plate at an angle of attack in axial high speed flow represents a prototypical control surface. Using a computationally efficient modal structural model coupled with a novel enhanced piston theory aerodynamic method, a nonlinear aeroelastic ...
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ConferenceAIAA Scitech 2021 Forum · January 1, 2021
Experiments were conducted to study the fluid-thermal-structural interactions of a compliant panel exposed to ramp-induced shock-wave/boundary-layer interactions (SWBLIs) at Mach 6 for laminar and transitional incoming boundary-layers. For some cases, boun ...
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ConferenceAIAA Scitech 2021 Forum · January 1, 2021
Presented is an automatic differentiation based nonlinear reduced-order modeling technique which includes geometric variation computation capability. The method is based on a Taylor series expansion of a nonlinear frequency-domain harmonic balance based co ...
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Conference32nd Congress of the International Council of the Aeronautical Sciences Icas 2021 · January 1, 2021
The spatial scheme method and adaptive mesh technique are chosen directly to determine the accuracy of the shock capture. Judging the correctness of one scheme by one dimensional Burgers equation is probably not enough for some real situation. A benchmark ...
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ConferenceAIAA Aviation and Aeronautics Forum and Exposition AIAA Aviation Forum 2021 · January 1, 2021
We have recently developed an automatic differentiation based nonlinear reduced-order modeling technique. The method is based on a Taylor series expansion of a nonlinear frequencydomain harmonic balance based computational fluid dynamic solver residual. In ...
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ConferenceAIAA Scitech 2020 Forum · January 1, 2020
Presented is a methodology for numerically stabilizing harmonic balance based aeroelastic solution approaches. The governing harmonic balance based aeroelastic equations are a stationary/steady system of equations. In order to solve these equations, many r ...
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ConferenceAIAA Scitech 2020 Forum · January 1, 2020
The proper orthogonal decomposition (POD) provides a useful method for studying nonlinear fluid dynamics; however, the construction and use of the POD basis modes for Reduced Order Modeling (ROM) introduces several sources of error which can jeopardize the ...
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ConferenceAIAA Aviation 2020 Forum · January 1, 2020
We present the details of two primary research topics in the area of aeroelastic optimization that we are currently working on. The first topic is a new discrete adjoint aeroelastic design optimization solution methodology, which has a computational cost t ...
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ConferenceConference Proceedings of the Society for Experimental Mechanics Series · January 1, 2019
The nonlinear oscillations of a cantilever beam are studied with a theoretical computational model and the results are compared to experimental results obtained in a previous study. In order to explore the various possible nonlinear effects, the cantilever ...
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ConferenceJournal of Aerospace Information Systems · January 1, 2019
Modern computational fluid dynamic simulations of flows about naval vessels produce an enormous amount of flow-field data. The computations are performed in order to model details of the erratic unsteady flows that can occur about naval superstructures. Th ...
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ConferenceAIAA Scitech 2019 Forum · January 1, 2019
Within the framework of a linear mode (physical or theoretical/computational) the dynamic instability (flutter) of the system and the forced response of the system (due to gust excitation, for example) can be considered separately and there is no interacti ...
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ConferenceAIAA Journal · January 1, 2019
This paper presents a study of the shock buffet phenomenon on the RA16SC1 supercritical airfoil using the proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) modal approaches. The computational fluid dynamics simulation is validated, ...
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ConferenceLecture Notes in Electrical Engineering · January 1, 2019
By modeling an aero-refueling hose as a flexible pipe, an experimental research is performed on measuring the sectional bending stiffness of a flexible pipe withstanding a internal-pressurized fluid. A Revised Midpoint-Concentrate-Force-Loading Methodology ...
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ConferenceInternational Forum on Aeroelasticity and Structural Dynamics 2019 Ifasd 2019 · January 1, 2019
During the design and analysis of aircraft flutter boundaries are typically computed using the p-k iterations, k iterations, p iterations, or eigenvalue analysis, that require computationally expensive and numerically sensitive procedures especially for co ...
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ConferenceInternational Forum on Aeroelasticity and Structural Dynamics 2019 Ifasd 2019 · January 1, 2019
Development is ongoing of a new inextensible nonlinear beam and plate model to be used in aeroelastic analysis. Recently, the authors have described the theory and computations of the new structural model and have published data illustrating the responses ...
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ConferenceInternational Forum on Aeroelasticity and Structural Dynamics 2019 Ifasd 2019 · January 1, 2019
This document explores a fluid instability known as buffet, which occurs in the subsonic, transonic and supersonic/hypersonic regimes. Buffet has been observed in experiments and various computational studies, and yet its underlying physics are not well-es ...
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ConferenceInternational Forum on Aeroelasticity and Structural Dynamics 2019 Ifasd 2019 · January 1, 2019
Our experimental study sought to answer the question: how to maximize the piezoelectric power extraction of an aeroelastic system? A simple rectangular cantilever plate, which experiences non-linear aeroelastic limit cycle oscillations (LCO), was used as a ...
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ConferenceInternational Forum on Aeroelasticity and Structural Dynamics 2019 Ifasd 2019 · January 1, 2019
This work describes the use of a nonlinear computational structural model coupled with Piston Theory aerodynamics for the design of a panel flutter experiment in hypersonic flow. The goal of the experiment is to reach flutter onset within the available flo ...
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ConferenceAIAA Aviation 2019 Forum · January 1, 2019
The lower-bound and upper-bound transonic Mach numbers based upon metrics of efficiency are discussed using the concepts of temperature change and entropy change. For air, the Mach numbers from 0.845 to 1.205 are suggested as the transonic boundaries. Next ...
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ConferenceAIAA ASCE AHS ASC Structures Structural Dynamics and Materials Conference 2018 · January 1, 2018
Presented is a fixed point iteration approach for harmonic balance computational flow solver based nonlinear aeroelastic computations. The methodology allows for the aeroelastic governing equations to be solved simultaneously, in an iterative manner, along ...
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ConferenceAIAA ASCE AHS ASC Structures Structural Dynamics and Materials Conference 2018 · January 1, 2018
Typically, during the design, analysis, flight test phases aircraft flutter boundaries are computed using the p-k iterations, k iterations, p iterations, or eigenvalue analysis, all of which require computationally expensive and numerically sensitive proce ...
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ConferenceJournal of Aircraft · January 1, 2018
Aeroelastic systems including all-moving control surfaces and aircraft wings with stores may experience limit cycling caused by nonlinear structural and/or aerodynamic mechanisms. These systems are examined here via two different and complementary models, ...
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Conference2018 Modeling and Simulation Technologies Conference · January 1, 2018
In the following paper, we demonstrate the use of both proper orthogonal decomposition and Fourier series decomposition approaches for airwake dataset compression. The proper orthogonal decomposition method is used for compressing airwake data in the time- ...
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ConferenceProceedings of the ASME Design Engineering Technical Conference · January 1, 2018
The dynamic stability of a cantilevered beam actuated by a nonconservative follower force has previously been studied for its interesting dynamical properties and its applications to engineering designs such as thrusters. However, most of the literature co ...
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ConferenceProceedings of the 21st Australasian Fluid Mechanics Conference Afmc 2018 · January 1, 2018
This work discusses the design of a panel flutter experiment in a Mach 5.8 free-piston compression-heated Ludwieg tube. Small test duration, low freestream pressure and limited space available within the coreflow have driven the choice of boundary conditio ...
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ConferenceProceedings of SPIE the International Society for Optical Engineering · January 1, 2017
Solar sail is a high potential 'sailing craft' for interstellar exploration. The area of the first flight solar sail demonstrator named "IKAROS" is 200 square meters. Future interplanetary missions will require solar sails at least on the order of 10000 sq ...
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ConferenceProceedings of the ASME Design Engineering Technical Conference · January 1, 2017
In this study, analysis and results of linear and nonlinear aeroelastic of a cantilever beam subjected to the airflow as a model of a high aspect ratio wing are presented. A third-order nonlinear beam model is used as structural model to take into account ...
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ConferenceASME 2017 Dynamic Systems and Control Conference Dscc 2017 · January 1, 2017
A theoretical and computational model has been developed for the nonlinear motion of an inextensible beam undergoing large deflections for cantilevered and free-free boundary conditions. The inextensibility condition was enforced through a Lagrange multipl ...
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ConferenceASME 2017 Dynamic Systems and Control Conference Dscc 2017 · January 1, 2017
The behavior of a system comprised of two parallel plates coupled by a discrete, linear spring and damper is studied. Classical Modal Analysis (CMA) is used to illustrate this behavior, while specifically observing the effects of varying the stiffness and ...
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Conference17th International Forum on Aeroelasticity and Structural Dynamics Ifasd 2017 · January 1, 2017
In this work, we seek parametrically rich modes that can be used to analyze nonlinear systems for a continuous variation of operating conditions. Towards this end, based on the Modally Equivalent Perturbed System (MEPS) and the Degenerate Transformation (D ...
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ConferenceASME International Mechanical Engineering Congress and Exposition Proceedings Imece · January 1, 2015
The aerodynamic force between a bristle pack and a rotor should be considered in order to predict the stability of a rotor brush seal system. The high pressure flow region in a brush seal makes the interaction of bristle pack, leakage flow and rotor compli ...
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Conference2nd AIAA Spacecraft Structures Conference · January 1, 2015
Results from recent NASA sponsored research on the structural dynamics, stability, and control characteristics of heliogyro solar sails are summarized. Specific areas under investigation include coupled nonlinear finite element analysis of heliogyro membra ...
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Conference56th AIAA ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2015
Fighter aircraft encounter aeroelastic Limit Cycle Oscillations (LCO) when carrying certain combinations of under-wing stores, leading to structural fatigue, pilot discomfort and flight envelope restrictions. The roles of various aerodynamic and structural ...
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Conference16th AIAA Issmo Multidisciplinary Analysis and Optimization Conference · January 1, 2015
Presented is a discrete adjoint method for transonic buffet design optimization. The method is based on a frequency do-main approach for modeling unsteady aerodynamics. Automatic differentiation is used to derive the computer code representing the adjoint ...
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Conference56th AIAA ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2015
Conical shell theory and a supersonic potential flow aerodynamic theory are used to study the nonlinear pressure buckling and aeroelastic limit cycle behavior of the thermal protection system for NASA’s Hypersonic Inflatable Aerodynamic Decelerator. The st ...
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ConferenceAIAA Journal · October 1, 2014
Aircraft wings carrying stores are susceptible to nonlinear aeroelastic limit-cycle oscillations, which can lead to reduced flight and mission performance. Limit-cycle-oscillation dynamics and control simulation studies, although of great importance, are o ...
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ConferenceAIAA Aviation 2014 15th AIAA Issmo Multidisciplinary Analysis and Optimization Conference · January 1, 2014
Using aeroelastic flutter geometric design sensitivities provided by a recently developed discrete adjoint aeroelastic solver, the shape of a NLR 7301 airfoil section is optimized to increase flutter onset velocity for a benchmark transonic aeroelastic con ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · August 15, 2013
Presented is a discrete adjoint approach for computing nonlinear aeroelastic design sensitivities for transonic and viscous flows based on Reynolds Averaged Navier-Stokes computational fluid dynamic models. The method is based on a harmonic balance nonline ...
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Conference54th AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · August 2, 2013
Presented is a discrete adjoint approach for computing nonlinear aeroelastic design sensitivities for transonic and viscous flows based on Reynolds Averaged Navier-Stokes computational fluid dynamic models. The method is based on a harmonic balance nonline ...
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ConferenceIfasd 2013 International Forum on Aeroelasticity and Structural Dynamics · January 1, 2013
The model of a nonlinear plate in a supersonic unsteady flow forced by a dynamic excitation and subject to a biaxial compressive load is considered. Indeed, the aeroelastic model can represent a variety of mechanical systems and it gives the opportunity to ...
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Conference50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition · December 1, 2012
This paper discusses the development and implementation of an automatic differentiation based nonlinear reduced order model for unsteady separated flows. The objective of the research presented herein has been to test the capability and limits of the metho ...
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Conference53rd AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference 2012 · January 1, 2012
Computer simulations are performed to determine the responses of a single DOF pitch airfoil system, as well as those of a two DOF pitch-and-heave system, in buffeting flows. The buffeting flow exhibits shock-wave oscillations of a unique frequency that occ ...
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Conference53rd AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference 2012 · January 1, 2012
In this paper, the impact of freeplay on flutter and limit-cycle oscillation (LCO) of an allmovable horizontal tail is studied. A 3D finite element model and a 3D finite volume model with unstructured gird of the all-movable horizontal tail are established ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · December 16, 2010
Presented are flutter-onset trends of the F-16 fighter computed using a harmonic balance version of the NASA OVERFLOW 2 flow solver code. The harmonic technique enables one to model unsteady aerodynamics and aeroelastic response in the frequency domain wit ...
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Conference19th AIAA Computational Fluid Dynamics Conference · January 1, 2009
A novel approach for implementing a nonlinear unsteady frequency domain harmonic balance solution technique about existing implicit computational fluid dynamic flow solvers is presented. This approach uses an explicit discretization of the harmonic balance ...
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ConferenceIcas Secretariat 26th Congress of International Council of the Aeronautical Sciences 2008 Icas 2008 · December 1, 2008
The state of reduced order modeling of unsteady aerodynamic flows for the efficient calculation of fluid-structure interaction (aeroelasticity) is discussed as well as very recent work on olecular dynamics simulations. Starting with either a time domain or ...
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ConferenceJournal of Computational Physics · June 1, 2008
A harmonic balance technique for the analysis of unsteady flows about helicopter rotors in forward flight and hover is presented in this paper. The aerodynamics of forward flight are highly nonlinear, with transonic flow on the advancing blade, subsonic fl ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · December 1, 2006
A computational investigation of flutter onset and limit cycle oscillations of the F-16 fighter using a nonlinear frequency-domain harmonic-balance approach is presented. In this latest study, we examine the sensitivity of computed aeroelastic behavior to ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2006
In recent years, new aeromechanical problems have been encountered in turbomachinery. In particular, non-synchronous vibrations (NSV) in blades have been observed by engine companies and occur as a result of flow instabilities. As a first step towards bett ...
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ConferenceCollection of Technical Papers 11th AIAA Issmo Multidisciplinary Analysis and Optimization Conference · January 1, 2006
Presented is a technique for developing a nonlinear reduced order model of a computational fluid dynamic solver. The method is based on a Taylor series expansion of a frequency domain harmonic balance computational fluid dynamic solver residual. The comput ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · December 19, 2005
A computational investigation of limit cycle oscillation behavior of the F-16 fighter configuration using a nonlinear frequency-domain harmonic-balance approach is presented. The research discussed in this latest paper is a follow-on to our work presented ...
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Conference12th International Congress on Sound and Vibration 2005 Icsv 2005 · December 1, 2005
The state of reduced order modeling of unsteady aerodynamic flows for the efficient calculation of fluid-structure interaction (aeroelasticity) is discussed. Reduced order modeling is a set of conceptually novel and computationally efficient techniques for ...
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Conference43rd AIAA Aerospace Sciences Meeting and Exhibit Meeting Papers · January 1, 2005
Two distinctly different reduced-order models are formulated for fully nonlinear aeroelastic systems. The first is based on Proper Orthogonal Decomposition (POD). The velocity field is decomposed into a finite number of orthonormal modes, effecting order r ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · December 1, 2004
A computational investigation of limit cycle oscillation behavior of the F-16 fighter configuration using a nonlinear frequency-domain harmonic-balance approach is presented. Computed limit cycle response results correlate well with experiment. Details of ...
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Conference41st Aerospace Sciences Meeting and Exhibit · December 1, 2003
Presented is a discrete adjoint approach for computing steady and unsteady aerodynamic design sensitivities for compressible viscous flows about airfoil configurations. The nominal flow solver method is based on a harmonic balance solution technique, which ...
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Conference44th AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · December 1, 2003
Presented is an investigation into the modeling of limit cycle oscillation (LCO) behavior of an experimental transonic airfoil aeroelastic configuration using a frequency-domain harmonic-balance (HB) computational fluid dynamic (CFD) approach. The aeroelas ...
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Conference41st Aerospace Sciences Meeting and Exhibit · January 1, 2003
Presented is a discrete adjoint approach for computing steady and unsteady aerodynamic design sensitivities for compressible viscous flows about airfoil configurations. The nominal flow solver method is based on a harmonic balance solution technique, which ...
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Conference44th AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2003
Nonlinear aeroelasticity is a subject of high interest and activity. In this paper the authors aim is to provide a faithful account of the topic with an emphasis on key ideas and results which demonstrate our community's current theoretical, computational ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2003
Presented is an investigation into the modeling of limit cycle oscillation (LCO) behavior of an experimental transonic airfoil aeroelastic configuration using a frequency-domain harmonic-balance (HB) computational fluid dynamic (CFD) approach. The aeroelas ...
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Conference40th AIAA Aerospace Sciences Meeting and Exhibit · January 1, 2002
In this first Von Karman Lecture of the twenty first century, a subject is addressed whose foundations were significantly influenced by the work of Theodore Von Karman. A classic paper by Von Karman and Sears first considered the determination of aerodynam ...
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ConferenceASME International Mechanical Engineering Congress and Exposition Proceedings · January 1, 2002
Presented is a frequency domain harmonic balance (HB) technique for modeling nonlinear unsteady aerodynamics of three-dimensional transonic inviscid flows about wing configurations. The method can be used to model efficiently nonlinear unsteady aerodynamic ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2002
Presented is a harmonic-balance (HB) computational fluid dynamic (CFD) approach for modeling limit cycle oscillation (LCO) behavior of aeroelastic airfoil configurations in a viscous transonic flow. For the NLM 7301 airfoil configuration studied, accountin ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2002
A parameter study of transonic airfoil flutter and limit cycle oscillation (LCO) behavior was presented. The effect of structural parameters and freestream Mach number of a transonic flow on the flutter and LCO was found out using inviscid computational fl ...
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Conference19th AIAA Applied Aerodynamics Conference · December 1, 2001
Limit cycle oscillations have been observed in flight operations of modern aircraft, wind tunnel experiments and mathematical models. Both fluid and structural nonlinearities are thought to contribute to these phenomena. With recent advances in reduced ord ...
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Conference19th AIAA Applied Aerodynamics Conference · December 1, 2001
The proper orthogonal decomposition (POD) based reduced order modeling (ROM) technique for modeling unsteady frequency domain aerodynamics is developed for a large scale computational model of an inviscid flow transonic wing configuration. Using the method ...
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Conference19th AIAA Applied Aerodynamics Conference · December 1, 2001
Using a state of the art computational fluid dynamic (CFD) method to model nonlinear steady and unsteady transonic flows in conjunction with a linear structural model, an investigation is made into how nonlinear aerodynamics can effect the divergence, flut ...
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Conference39th Aerospace Sciences Meeting and Exhibit · December 1, 2001
Presented is a newly devised static/dynamic correction approach for eigenvector expansion based reduced-order modeling (ROM). When compared to the fundamental Ritz ROM formulation, along with the static and multiple static correction ROM approaches, the te ...
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ConferenceProceedings of the ASME Turbo Expo · January 1, 2001
An unsteady inviscid flow through a cascade of oscillating airfoils is investigated. An inviscid nonlinear subsonic and transonic model is used to compute the steady flow solution. Then a small amplitude motion of the airfoils about their steady flow confi ...
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Conference19th AIAA Applied Aerodynamics Conference · January 1, 2001
The proper orthogonal decomposition (POD) based reduced order modeling (ROM) technique for modeling unsteady frequency domain aerodynamics is developed for a large scale computational model of an inviscid flow transonic wing configuration. Using the method ...
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Conference19th AIAA Applied Aerodynamics Conference · January 1, 2001
Limit cycle oscillations have been observed in flight operations of modern aircraft, wind tunnel experiments and mathematical models. Both fluid and structural nonlinearities are thought to contribute to these phenomena. With recent advances in reduced ord ...
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Conference19th AIAA Applied Aerodynamics Conference · January 1, 2001
Using a state of the art computational fluid dynamic (CFD) method to model nonlinear steady and unsteady transonic flows in conjunction with a linear structural model, an investigation is made into how nonlinear aerodynamics can effect the divergence, flut ...
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Conference19th AIAA Applied Aerodynamics Conference · January 1, 2001
Discrete time aeroelastic models with explicitly retained aerodynamic modes have been generated employing a time marching vortex lattice aerodynamic model. This paper presents analytical results from eigenanalysis of these models. The potential of these mo ...
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Conference39th Aerospace Sciences Meeting and Exhibit · January 1, 2001
Presented is a newly devised static/dynamic correction approach for eigenvector expansion based reduced-order modeling (ROM). When compared to the fundamental Ritz ROM formulation, along with the static and multiple static correction ROM approaches, the te ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2001
The proper orthogonal decomposition (POD) based reduced order modeling (ROM) technique for modeling unsteady frequency domain aerodynamics is developed for a large scale computational model of an inviscid flow transonic wing configuration. Using the method ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2001
Limit cycle oscillations have been observed in flight operations of modern aircraft, wind tunnel experiments and mathematical models. Both fluid and structural nonlinearities are thought to contribute to these phenomena. With recent advances in reduced ord ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 2001
Using a state of the art computational fluid dynamic (CFD) method to model nonlinear steady and unsteady transonic flows in conjunction with a linear structural model, an investigation is made into how nonlinear aerodynamics can effect the divergence, flut ...
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Conference41st Structures Structural Dynamics and Materials Conference and Exhibit · January 1, 2000
A nonlinear response analysis of a typical airfoil section with control surface freeplay excited by periodic gust loads in low subsonic flow is presented along with a companion wind tunnel test program. The analytical model uses Peters' finite state model ...
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Conference41st Structures Structural Dynamics and Materials Conference and Exhibit · January 1, 2000
A method for investigating the degree of stability of nonlinear limit cycle oscillations (LCO) observed in an aeroelastic system is presented. The system considered is a typical section airfoil model with a free-play nonlinear-ity in the control surface st ...
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ConferenceASME International Mechanical Engineering Congress and Exposition Proceedings Imece · January 1, 2000
Limit cycle oscillations(LCO) have been observed in flight for certain modern high performance aircraft. The nonlinear physical mechanism responsible for the LCO is still in doubt, even to the point of it not yet being determined whether the nonlinearity i ...
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Conference37th Aerospace Sciences Meeting and Exhibit · January 1, 1999
A new method for constructing reduced-order models (ROM) of unsteady small-disturbance flows is presented. The reduced-order models are constructed using basis vectors determined from the proper orthogonal decomposition (POD) of an ensemble of small-distur ...
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ConferenceASME International Mechanical Engineering Congress and Exposition Proceedings Imece · January 1, 1999
The proper orthogonal decomposition technique is applied in the frequency domain to obtain reduced order models (ROM) of the flow in a cascade of airfoils. The flow is described by a inviscid-viscous interaction model where the inviscid part is described b ...
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ConferenceAmerican Society of Mechanical Engineers, Fluids Engineering Division (Publication) FED · 1999
The proper orthogonal decomposition technique is applied in the frequency domain to obtain reduced order models (ROM) of the flow in a cascade of airfoils. The flow is described by a inviscid-viscous interaction model where the inviscid part is described b ...
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ConferenceCollection of Technical Papers AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference · January 1, 1999
A review is given on the status of reduced order modeling of unsteady aerodynamic systems. Starting with either a time domain or frequency domain computational fluid dynamics (CFD) analysis of unsteady aerodynamic flows, a large, sparse eigenvalue is solve ...
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ConferenceAmerican Society of Mechanical Engineers Aerospace Division Publication AD · December 1, 1997
In this article, we review the status of reduced order modeling of unsteady aerodynamic systems. Reduced order modeling is a conceptually novel and computationally efficient technique for computing unsteady flow about isolated airfoils, wings, and turbomac ...
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Conference35th Aerospace Sciences Meeting and Exhibit · January 1, 1997
This paper presents a correlation study between numerical and experimental results for the response of a typical section airfoil with freeplay in the control surface. Since this is an inherently nonlinear system the equations of motion are integrated numer ...
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ConferenceASME International Mechanical Engineering Congress and Exposition Proceedings Imece · January 1, 1997
In this article, we review the status of reduced order modeling of unsteady aerodynamic systems. Reduced order modeling is a conceptually novel and computationally efficient technique for computing unsteady flow about isolated airfoils, wings, and turbomac ...
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Conference34th Aerospace Sciences Meeting and Exhibit · January 1, 1996
Fluid eigenmodes can be used to construct extremely efficient reduced order unsteady aerodynamic models of the Euler equations, which can also be used to perform highly efficient aeroelastic analyses. This is done by transforming the large set of primitive ...
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Conference9th Computational Fluid Dynamics Conference 1989 · January 1, 1989
A method is proposed to determine directly the amount of artificial viscosity needed for stability using an eigenvalue analysis for a finite difference representation of the Navier-Stokes equations. The stability and growth of small perturbations about a s ...
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ConferenceAmerican Society of Mechanical Engineers (Paper) · January 1, 1978
There are several well-known results due to Rayleigh left bracket 1 right bracket on the effects of mass and stiffness addition to a dynamical system. In this paper these results are reconsidered and generalized using the methods previously employed by the ...
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