1,721,234 research outputs found
Appunti per biologi su cristalli e minerali. Metodi non distruttivi per la loro identificazione
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Given a wingspan, which windplane design maximizes power?
Full text linkWindplanes (i.e. Fly-Gen airborne wind energy systems) harvest wind power via the turbines placed on the tethered wing, which flies crosswind trajectories. In this paper, the optimal design of windplanes is investigated with simplified models, enabling an intuitive understanding of their physical characteristics. The windplane is then idealized as a point mass flying circular fully crosswind trajectories. If the gravity is neglected, the dynamic problem is axial symmetric and the solution is steady. The generated power can be expressed in non-dimensional form by normalizing it with the wind power passing by a disk with radius the wingspan. Since the reference area is taken to be a function of just the wingspan, looking for the design which maximizes this power coefficient addresses the question "Given a wingspan, which design maximizes power?". This is different from the literature, where the design problem is formulated per wing area and not per wingspan. The optimal designs have a finite aspect ratio and operate at the maximum lift-to-drag ratio of the airfoil. Airfoils maximizing the lift-to-drag ratio are then optimal for windplanes. If gravity is included in the model, gravitational potential energy is being exchanged over one revolution. Since this exchange comes with an associated efficiency, the plane mass and the related trajectory radius are designed to reduce the potential energy fluctuating over the loop. However, for decreasing turning radii, the available wind power decreases because the windplane sweeps a lower area. For these two conflicting reasons, the optimal mass is finite
A Direct Transcription Method for the Solution of Inverse Dynamics and Trajectory Optimization Problems of Multibody Systems
No full textOn the Solution of Inverse Dynamics and Trajectory Optimization Problems for Multibody Systems Using Energy-Consistent Methods
No full textOptimal Control of Multibody Systems Using an Energy Preserving Direct Transcription Method
No full textSimulation and Control of Maneuvering Vehicles with Application to Rotorcraft Emergency Landings
No full textMultibody Inverse Dynamics Using an Energy Preserving Direct Transcription Process
No full textWe propose a procedure for the solution of inverse multibody dynamic problems, here intended as optimal control problems for dynamical systems governed by differential-algebraic equations. The numerical solution is obtained by a direct transcription process based on an energy preserving scheme that ensures non-linear unconditional stability. The resulting finite-dimensional problem is solved by sequential quadratic programming. We test the proposed methodology with the help of representative examples
Steering of Flexible Multibody Systems with Application to the Maneuvering Flight of Rotorcraft Vehicles
No full textWind Tunnel Testing of Aero-Elastically Scaled Wind Turbine Blades with Active and Passive Control Systems
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