Feathers can produce sound by fluttering in airflow. This flutter is hypothesized to be aeroelastic, arising from the coupling of aerodynamic forces to one or more of the feather's intrinsic structural resonance frequencies. We investigated how mode of flutter varied among a sample of hummingbird tail feathers tested in a wind tunnel. Feather vibration was measured directly at ~100 points acros...

A study of multidisciplinary design concerning the incorporation of aeroelastic tailoring, control surface blending, and active aeroelastic wing concepts is presented. The design process incorporates response surfaces, fast probability integration and modal-basis multidisciplinary design optimization to characterize the design space. The wing box skins of a representative fighter configuration ...

By combining the aeroelastic and vortex-forced flutter modes of a thin plastic strip, its oscillation frequency can be confined to scale monotonically with fluid velocity. This principle has been used to produce a low-cost, mm-scale anemometer that measures air speed to ±(5% + 0.5m/s) from 118m/s. The device uses a 2mm slot-type photointerrupt detector to monitor the fundamental frequency of a ...

System identification methods for non-linear aeroelastic systems could find uses in many aeroelastic applications such as validating finite element models and tracking the stability of aircraft during flight flutter testing. The effectiveness of existing non-linear system identification techniques is limited by various factors such as the complexity of the system under investigation and the typ...

This paper presents investigation effects of a sharp edged gust on aeroelastic behavior and time-domain response of a typical section model using Jones approximate aerodynamics for pure plunging motion. Flutter analysis has been done by using p and p-k methods developed for presented finite-state aerodynamic model for a typical section model (airfoil). Introduction of gust analysis as a linear ...

This paper proposes Reduced-Order Models (ROMs) based on data provided by Computational Fluid Dynamics (CFD) simulations for generally flexible tanks to be embedded in a larger aerospace structure. A commercial off-the-shelf CFD code addressed sloshing analyses is employed generate set used the synthesis of system ROM. The developed ROM, Linearized Frequency Domain (LFD) approach, makes use an ...

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 ...

Introduction Cable stayed bridges are a feasible choice for middle length spans and can be also an alternative to suspension bridges in the range of 1000 m spans. In the last three years, cable stayed bridges having more than 1 km span have been built in China (Sutong Bridge, 1088 m and Stonecutters Bridge, 1018 km). The increasing in length implies higher aeroelastic interaction with wind acti...

A high-fidelity numerical formulation is presented for the high-speed aeroelastic behavior of slender composite wings. The compressible flow is modeled using the 3-D Euler equations on a deformable mesh, and an asymptotic approximation of the 3-D kinematically-nonlinear equations of elasticity models the anisotropic slender structure. The transfer of the distributed loads and displacements at t...