scholarly journals A Hybrid Reduced-Order Model for the Aeroelastic Analysis of Flexible Subsonic Wings—A Parametric Assessment

Aerospace ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 76 ◽  
Author(s):  
Marco Berci ◽  
Rauno Cavallaro
Keyword(s):  
Structural Parameters ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Unsteady Aerodynamics ◽  
Reduced Order Model ◽  
Order Model ◽  
Flexible Wings ◽  
Reduced Order ◽  
Aeroelastic Analysis ◽  
Strip Theory

A hybrid reduced-order model for the aeroelastic analysis of flexible subsonic wings with arbitrary planform is presented within a generalised quasi-analytical formulation, where a slender beam is considered as the linear structural dynamics model. A modified strip theory is proposed for modelling the unsteady aerodynamics of the wing in incompressible flow, where thin aerofoil theory is corrected by a higher-fidelity model in order to account for three-dimensional effects on both distribution and deficiency of the sectional air load. Given a unit angle of attack, approximate expressions for the lift decay and build-up are then adopted within a linear framework, where the two effects are separately calculated and later combined. Finally, a modal approach is employed to write the generalised equations of motion in state-space form. Numerical results were obtained and critically discussed for the aeroelastic stability analysis of a uniform rectangular wing, with respect to the relevant aerodynamic and structural parameters. The proposed hybrid model provides sound theoretical insights and is well suited as an efficient parametric reduced-order aeroelastic tool for the preliminary multidisciplinary design and optimisation of flexible wings in the subsonic regime.

The Study of Aeroelastic Reduced-Order Model Based on CFD/CSD Method and its Application

2014 ◽  
Vol 978 ◽  
pp. 131-134
Author(s):  
Rui Li ◽  
Chang Hong Tang
Keyword(s):  
Harmonic Balance ◽  
Unsteady Aerodynamics ◽  
Harmonic Balance Method ◽  
Reduced Order Model ◽  
Reduced Order Models ◽  
Order Model ◽  
Reduced Order ◽  
Advantages And Disadvantages ◽  
Aeroelastic Analysis ◽  
Proper Orthogonal

Unsteady aerodynamics research is the foundation of aeroelastic analysis. How to effectively improve the aeroelastic computational efficiency,it is the key of current research on aeroelasticity now.Reduced order models are proposed as a powerful tool to solve this problem. Analyzed the three reduced-order models for Volterra ,Proper Orthogonal Decomposition and Harmonic Balance method ,their advantages and disadvantages were pointed out. The direction of the reduced order model in the future was Proposed and some suggest was given out for its application.

scholarly journals A Reduced-Order Model for the Vibration Analysis of Mistuned Blade–Disc–Shaft Assembly

2019 ◽  
Vol 9 (22) ◽  
pp. 4762
Author(s):  
Wang ◽  
Bi ◽  
Zheng
Keyword(s):  
Vibration Analysis ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Normal Modes ◽  
Order Reduction ◽  
Symmetry Analysis ◽  
Reduced Order Model ◽  
Cyclic Symmetry ◽  
Order Model ◽  
Reduced Order

An effective reduced-order model is presented in this paper for the vibration analysis of a mistuned blade–disc–shaft assembly considering the flexibility of the shaft and the rotordynamic effects. For the sake of accurate modeling and quantitative analysis, three-dimensional (3D) finite element models were employed in obtaining the governing equations of motion with the Coriolis force, centrifugal stiffening, and spin softening effects taken into account. Then, an efficient model order reduction technique based on the coordinate projection by normal modes of tuned assembly and cyclic symmetry analysis was developed for mistuned blade–disc–shaft assembly. The criterion of whether one matrix could be incorporated in cyclic symmetry analysis is presented. During the modeling, the mistuning in blade and disc was taken into account and dealt with independently. In mistuning projection, the blade and disc parts were both projected onto their tuned counterparts of the sector model, where the boundary conditions were set to be fixed and free, respectively. Finally, an example of a blade–disc–shaft assembly was employed to validate the effectiveness of the presented method in free and forced vibration analysis.

A Reduced Order Model for the Aeroelastic Analysis of Flexible Wings

2013 ◽  
Vol 6 (2) ◽  
pp. 447-458 ◽  
Author(s):  
Enrico Cestino ◽  
Giacomo Frulla ◽  
Piergiovanni Marzocca
Keyword(s):  
Reduced Order Model ◽  
Order Model ◽  
Flexible Wings ◽  
Reduced Order ◽  
Aeroelastic Analysis

Decentralized Control of a Tower Crane

1999 ◽  
Author(s):  
Kiyoshi Takagi ◽  
Hidekazu Nishimura
Keyword(s):  
Decentralized Control ◽  
Three Dimensional ◽  
Reduced Order Model ◽  
Flexible Structure ◽  
Order Model ◽  
Modeling And Control ◽  
Reduced Order ◽  
Tower Crane ◽  
Three Dimensional Models ◽  
And Control

Abstract This paper deals with modeling and control of a crane mounted on a tower-like flexible structure. A fast transfer of the load causes the sway of the load rope and the vibration of the flexible structure. Our object is to control both the sway and the vibration by the inherent capability of the tower crane. This paper makes its three-dimensional models for simulation and reduced-order-model in order to design the decentralized control system. Then, we design the decentralized H∞ compensator and verify the efficiency by simulations and experiments.

Design of a Kangaroo Inspired Hopping Robot for Unrestricted Locomotion and Controller Development

2019 ◽  
Author(s):  
Austin Curtis ◽  
James Mynderse ◽  
Hamid Vejdani
Keyword(s):  
Frequency Response ◽  
Three Dimensional ◽  
Reduced Order Model ◽  
Design Parameters ◽  
Order Model ◽  
Reduced Order ◽  
Gait Performance ◽  
System Parameters ◽  
Hopping Robot ◽  
The Relationship

Abstract Inspired by the agility and maneuverability of running kangaroos, a prototype robot was developed using a reduced order model to constrain the system. Both passive and active models were used to understand the relationship between system parameters and gait performance. A frequency response experiment was performed on the prototype to quantify the relationship between design parameters and system responses. Additionally, preliminary tail controllers were tested. Based on the results of the initial platform, a new robot was designed and built as a platform for the study of three dimensional hopping.

Linear Reduced-Order Model for Unsteady Aerodynamics of an L-Shaped Gurney Flap

2015 ◽  
Vol 52 (6) ◽  
pp. 1887-1904 ◽  
Author(s):  
Valentina Motta ◽  
Giuseppe Quaranta
Keyword(s):  
Unsteady Aerodynamics ◽  
Reduced Order Model ◽  
Order Model ◽  
Reduced Order ◽  
Gurney Flap

Reduced Order Model of Two Coupled MEMS Parallel Cantilever Resonators Under DC and AC Voltage Near Natural Frequency

2012 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Kyle N. Taylor
Keyword(s):  
Frequency Response ◽  
Natural Frequency ◽  
Multiple Scales ◽  
Equations Of Motion ◽  
Reduced Order Model ◽  
Lagrange Equations ◽  
Order Model ◽  
Reduced Order ◽  
Dc Voltage ◽  
Ground Plate

This paper deals with a system of two coupled parallel identical MEMS cantilever resonators and a ground plate. Alternating Current (AC) and Direct Current (DC) voltages are applied between the first resonator and ground plate, and a DC voltage applied between the resonators. The AC voltage frequency is near natural frequency of the resonators. The electrostatic forces produced by voltages are nonlinear. System equations of motion are obtained using Lagrange equations, then nondimensionalized. The Method of Multiple Scales (MMS) is used to find the steady state frequency response. The Reduced Order Model (ROM) is used to validate MMS results. Matlab is used to find cantilever frequency response of the resonator tip. The DC voltage between resonators is showed to significantly influence the response of the first resonator.

Aeroelastic Analysis of Blades Cascades Through Aerodynamic Reduced-Order Modeling

2011 ◽  
Author(s):  
Davide Finamore ◽  
Fred Nitzsche ◽  
Massimo Gennaretti
Keyword(s):  
Reduced Order Model ◽  
Aeroelastic Stability ◽  
Order Model ◽  
Control Laws ◽  
Reduced Order ◽  
Aerodynamic Model ◽  
Blade Cascade ◽  
Aeroelastic Analysis ◽  
Direct Use ◽  
High Computational Efficiency

An aerodynamic Reduced-Order Model (ROM) is introduced to describe the aeroelastic behavior of a blade cascade of a turbomachine. This is obtained coupling an aerodynamic model with a semi-rigid 2D model for the description of the structure dynamics. The advantages of using an aerodynamic reduced-order model concern the high computational efficiency compared to the direct use of a CFD code, and the applicability of control laws to reduce, for instance, blades vibrations. ROMs are identified from both an analytical aerodynamic model and a numerical CFD solver. The aeroelastic stability of a blade cascade is examined with the presence or not of mistuning.

A Method for Reducing the Order of Nonlinear Dynamic Systems

1984 ◽  
Vol 51 (2) ◽  
pp. 391-398 ◽  
Author(s):  
S. F. Masri ◽  
R. K. Miller ◽  
H. Sassi ◽  
T. K. Caughey
Keyword(s):  
Dynamic Systems ◽  
Three Dimensional ◽  
Element Model ◽  
Random Excitation ◽  
Reduced Order Model ◽  
Order Model ◽  
Reduced Order ◽  
Dimensional Finite Element ◽  
Restoring Forces ◽  
Three Dimensional Finite Element

An approximate method that uses conventional condensation techniques for linear systems together with the nonparametric identification of the reduced-order model generalized nonlinear restoring forces is presented for reducing the order of discrete multidegree-of-freedom dynamic systems that possess arbitrary nonlinear characteristics. The utility of the proposed method is demonstrated by considering a redundant three-dimensional finite-element model half of whose elements incorporate hysteretic properties. A nonlinear reduced-order model, of one-third the order of the original model, is developed on the basis of wideband stationary random excitation and the validity of the reduced-order model is subsequently demonstrated by its ability to predict with adequate accuracy the transient response of the original nonlinear model under a different nonstationary random excitation.

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