Global ETD Search
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Showing 1 to 18 of 18 for “"Aerodynamic Modeling"”.
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Unsteady Nonlinear Aerodynamic Modeling and Applications
Unsteady aerodynamic modeling is indispensable in the design process of rotary air vehicles, flapping flight and agile unmanned aerial vehicles. Undesirable vibrations can cause high-frequency variations in motion variables whose effects cannot be well predicted using quasi-steady aerodynamics. …
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Micro air vehicle motion tracking and aerodynamic modeling
Aerodynamic performance of small-scale fixed-wing flight is not well understood, and flight data are needed to gain a better understanding of the aerodynamics of micro air vehicles (MAVs) flying at Reynolds numbers between 10,000 and 30,000. Experimental studies have shown the aerodynamic effects …
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Rapid-response surveillance system design and aerodynamic modeling
… ballistic trajectory, to de-spin and slow down. Aerodynamic surfaces (wings and tails) would deploy out of the shell, and the flier would conduct a 15-minute surveillance mission, recording images with a visual sensor, and sending them back to a ground station. In the aerodynamic analysis and …
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Aerodynamic Modeling Using Computational Fluid Dynamics and Sensitivity Equations
A mathematical model for the determination of the aerodynamic forces acting on an aircraft is presented. The mathematical model is based on the generalization of the idea of aerodynamically steady motions. One important use of these results is the determination of steady (time-invariant) …
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A Numerical Vortex Approach To Aerodynamic Modeling of SUAV/VTOL Aircraft
… presented as a low-cost approach to preliminary modeling of slipstream effects on a finite wing. The wing aerodynamic model employs a numerical lifting-line method utilizing the 3D vortex lifting law along with known 2D airfoil data to predict the lift distribution across a wing for a prescribed …
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Aerodynamic modeling and assessment of flaps for hypersonic trajectory control of blunt bodies
Independently articulated aerodynamic flaps on a blunt-body entry vehicle may provide a feasible alternative to current state-of-the-art bank-angle steering control while introducing additional benefits during entry, descent, and landing. Flaps provide direct control of the vehicle’s lift and drag …
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Aerodynamic Modeling in Nonlinear Regions, including Stall Spins, for Fixed-Wing Unmanned Aircraft from Experimental Flight Data
… opportunities exist to create high-fidelity aerodynamic models with flight test techniques developed specifically for remotely piloted aircraft. Then, highly maneuverable unmanned aircraft can be employed to their greatest potential in a safe manner using advanced control laws. In this …
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Aerodynamic modeling of a 2-dimensional airfoil with a covert-inspired deployable flap using a discrete vortex method
Unmanned aerial vehicles are expected to fulfill increasingly complex mission requirements but are limited by their inability to efficiently perform high-angle-of-attack maneuvers at low Reynolds numbers, while birds seem to perform these maneuvers with little effort. Birds use a passively-deployed …
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In-flight estimation of environmental and aerodynamic modeling errors for a GPS-INS guided artillery shell in a GPS-jamming environment
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1998.
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Design, Development, and Analysis of a Morphing Aircraft Model for Wind Tunnel Experimentation
… shape variations for fundamental research in modeling and control of morphing air vehicles. The vehicle is designed for five primary purposes: quasi-steady aerodynamic modeling of an aircraft with large planform changes, optimization studies in achieving efficient flight configurations, …
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INTEGRATION OF PHYSICS-INFORMED APPROACHES WITH MACHINE LEARNING TECHNIQUES FOR AERODYNAMICS
… learning techniques and physics laws to tackle aerodynamic challenges. Specifically, it employs machine learning methodologies to enhance various aspects of aerodynamics, including the optimization of airfoil designs, prediction of 2D flow fields, and refinement of flush air data sensing …
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Integrated aerodynamic-structural wing design optimization
Several procedures for the simultaneous aerodynamic-structural design optimization of aircraft wings are investigated. These procedures include efficient methods for optimization and sensitivity calculations that are applied to two specific design examples. The first is a subsonic transport …
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L1 adaptive control within Learn-to-Fly
… framework that was combined with real-time modeling and real-time guidance algorithms to test the feasibility of the NASA Learn-to-Fly concept. The objective of Learn-to-Fly is to reduce or eliminate the need for ground-based aerodynamic modeling in favor of in-flight modeling and control …
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Global Nonlinear Modeling Using Automated Local Model Networks in Real Time
Global nonlinear modeling is a challenging task that spans multiple disciplines. When it is necessary to develop a model across the global input space, and a single linear model is insufficient, nonlinear modeling methods are required. If the model is constrained to be developed autonomously in …
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An Aerodynamic Model for Use in the High Angle of Attack Regime
… a linear filter must be used to extract out the aerodynamic responses. To achieve this, a Finite Impulse Response (FIR) is designed using the Remez exchange algorithm. Based on the reduced data, a state–space model is developed to describe the unsteady aerodynamic characteristics of the aircraft …
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Reduced-order modeling of aeroelastic phenomena
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2023-12-04 without embargo terms
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System Identification of a Nonlinear Flight Dynamics Model for a Small, Fixed-Wing UAV
… incorporation of information from computational aerodynamics and synthesis of information from different flight test maneuvers. The final parameter estimation and uncertainty analysis was developed from the time domain formulation of the output-error method using the fully nonlinear aircraft …
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Ducted Fan Aerodynamics and Modeling, with Applications of Steady and Synthetic Jet Flow Control
… a target is essential. However, the ducted fan's aerodynamic characteristics pose difficulties for stable vehicle flight and therefore require complex control algorithms. In particular, they exhibit a large nose-up pitching moment during wind gusts and when transitioning from hover to forward …