An embedded-boundary Cartesian-mesh flow solver is coupled with a three degree-offreedom structural model to perform static, aeroelastic analysis of complex aircraft geometries. The approach solves the complete system of aero-structural equations using a modular, loosely-coupled strategy which allows the lower-fidelity structural model to deform the highfidelity CFD model. The approach uses an ...

This paper introduces an approach to effectively model the nonlinear aeroelastic behavior of fully flexible aircraft. The study is conducted based on a nonlinear strainedbased finite element framework in which the developed low-order formulation captures the nonlinear (large) deflection behavior of the wings, and the unsteady subsonic aerodynamic forces acting on them. Instead of merely conside...

Simulation models of a variable-speed, fixed-pitch wind turbine were investigated to evaluate the feasibility of constraining rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracte...

Uncertainties associated with the load effects and dynamic characteristics of wind-excited structures have been identified and discussed Based on the available experimental data from laboratory and field study measurements the variability of the parameter space categorized as wind environment and meteorological data, wind-structure interaction and structural properties has been assessed The pro...

Dynamic stall is an aerodynamic phenomenon encountered when rotorcraft operate near performance boundaries typical of high-speed or maneuvering flight. The complex, highly non-linear aerodynamics and associated interaction with the structures induce exceptionally high loads, violent vibrations, reduced handling qualities, and a reduction in fatigue life. The prediction of dynamic stall remains ...

The purpose of the current test program is to produce a new dataset with sufficient documentation to be useful for correlation, development, and refinement of aerodynamic models at high thrust. An aerodynamic limits test was conducted in the 7by 10-Foot Wind Tunnel at Ames Research Center. The objectives of the test were to measure the performance and control loads of the rotor in nominal thrus...

This paper presents the study conducted to design and analyze a morphing trailing edge flap structure for a large aircraft wing. The rear part of the trailing edge flap was modified to be integrated with a set of internal actuation mechanisms distributed along the span of the flap. Additional changes to the conventional flap structure were implemented, such as an open sliding trailing edge and ...

This paper examines efficacy of tuned mass dampers ~TMD! in controlling self-excited motion resulting from negative damping. New optimal TMD parameters are suggested which provide better performance than those suggested in the literature. The dependence of TMD performance on structural damping is highlighted. The equations of motion of a combined system comprised of multiple TMDs attached to a ...

The blade pitch of a Vertical Axis Wind Turbine can have profound impact on the aerodynamic loading experienced by turbine. This in turn impacts structural loads and performance machine. In order to characterize effects changing pitch, studies are conducted with fixed offsets from neutral position open jet wind tunnel TU Delft. Measurements strain gages bonded turbine struts used estimate norma...

Wind loads on structures under the buffeting action of wind gusts have traditionally been treated by the ‘‘gust loading factor’’ (GLF) method in most major codes and standards around the world. In this scheme, the equivalent-static wind loading used for design is equal to the mean wind force multiplied by the GLF. Although the traditional GLF method ensures an accurate estimation of the displac...