An aeroelastic stability analysis is presented for high-aspect ratio composite wings. The structural model is based on an asymptotically correct crosssectional formulation and a nonlinear geometric exact beam analysis, both derivable from 3-D elasticity. A new 2-D unsteady inflow finite-state theory is considered for the aerodynamic part of the solution. Theodorsen theory is also implemented an...

In this report four previously unpublished notes, concerned with aeroelastic effects on a particular slender delta aircraft configuration, are collected together. Some general flutter calculations show that decreasing stiffness leads to instability in the aircraft short period mode whilst the higher frequency modes remain stable. The reasons for the instability and the implications regarding ai...

This paper presents a frequency-limited adaptive controller design for an aeroelastic generic transport model. Specifically, the proposed framework consists of a new reference system and an adaptive controller. The proposed reference system captures a desired closed-loop dynamical system behavior modified by a mismatch term representing the highfrequency content between the uncertain dynamical ...

Aeroelastic instabilities are an important factor in the design of modern high-speed, flexible aircraft. The current trend is toward the creative use of composites to delay these instabilities. To obtain an optimum design, an accurate as well as efficient model is required. As a first step towards this goal, aeroelastic analysis is carried out for a swept composite box beam, using a linear stru...

In this work the aeroelastic stability of long-span bridge decks is numerically investigated. A simulation model is presented by which the aerodynamic fields and the structural motion are simultaneously and jointly simulated. The bridge deck is schematised as a bidimensional rigid body subject to elastic restraints corresponding to the torsional and the vertical degree of freedom, and the ALE f...

In this contribution, a new and efficient multivariate interpolation scheme is presented which is designed for large-scale coupling problems in the field of numerical aeroelasticity. The scheme is based upon a local application of radial basis functions (RBFs). The new method is tested in several numerical aeroelastic computations, and compared to a competing, widely used global approach. The i...

torsion of the gallbladder is a relatively rare surgical disease which mimics acute cholecystitis' symptoms that usually would not be respondable to medical therapies. the torsion would mostly be diagnosed intra-operatively. cholecystectomy is the treatment of choice. in general in our centre, general surgery department, imam reza hospital, mashhad, iran, since 1986 over 14000 cholecystect...

A frequency-domain lifting-line solution algorithm for the prediction of unsteady aerodynamics wings is presented. The Biot–Savart law applied to determine normalwash generated by wake vorticity distribution, whereas steady and airfoil theories (Glauert’s Theodorsen’s, respectively) are used evaluate sectional aerodynamic loads, namely lift pitching moment. released at trailing edge derives fro...

The model-free control of aeroelastic vibrations of a non-linear 2-D wing-flap system operating in supersonic flight speed regimes is discussed in this paper. A novel continuous robust controller design yields asymptotically stable vibration suppression in both the pitching and plunging degrees of freedom using the flap deflection as a control input. The controller also ensures that all system ...

The integration of loads analysis models using so called aerodynamic influence coefficients (AICs) is described. These AICs relate a change of normal velocity at panel control points to a change in panel pressure distribution, allowing to consider aeroelastic effects in a straight forward manner. The aerodynamic method employed for aeroelastic applications is typically the Vortex or Doublet Lat...