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Showing 1 to 15 of 15 for “"Unsteady Vortex Lattice Method"”.
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A numerical model of unsteady, subsonic aeroelastic behavior
A method for predicting unsteady, subsonic aeroelastic responses has been developed. The technique accounts for aerodynamic nonlinearities associated with angles of attack, vortex-dominated flow, static deformations, and unsteady behavior. The angle of attack is limited only by the occurrence of …
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Numerical simulations of wings in unsteady flows
The unsteady vortex-lattice method is used to calculate the pressure coefficients on thick and thin airfoils in steady and unsteady flowfields. The parameters which affect the results, such as time step and aspect ratio, are studied. The effects of Reynolds number and thickness of a wing in steady …
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A vortex-lattice method for Delta wing aerodynamics
… The lifting surface is modelled as a bound vortex sheet, while the wake is modelled as a force-free vortex sheet. The solution is obtained by the use of a unsteady Vortex-Lattice Method which includes the effect of leading edge separation. Numerical predictions for the aerodynamic loads and …
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Two-degree-of-freedom subsonic wing rock and nonlinear aerodynamic interference
… is the phenomenon of subsonic wing rock. A method has been developed that accurately simulates the pitching and rolling motions and accompanying unsteady flowfield for a slender delta wing. The method uses a predictor-corrector technique in conjunction with the general unsteady …
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Dynamical System Representation and Analysis of Unsteady Flow and Fluid-Structure Interactions
… utilized to reduce the representation order of unsteady fluid flows and fluid-structure interaction systems. This approach allows for significant reduction in the computational cost of their numerical simulations, implementation of optimization and control methodologies and assessment of their …
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Numerical Simulations of Interactions Among Aerodynamics, Structural Dynamics, and Control Systems
… performing numerical simulations of nonlinear unsteady aeroelastic behavior is developed. The technique is applied to long-span bridges and the wing of a modern business jet. The heart of the procedure is combining the aerodynamic and structural models. The aerodynamic model is a general …
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Hydrodynamic Study of Pisciform Locomotion with a Towed Biolocomotion Emulator
… proposes a reduced-order flow model using the unsteady vortex lattice method (UVLM) to predict the hydrodynamic performance of such a system. The proposed model is then validated with the experimental data collected earlier. The tool developed can be employed to quickly explore the possible …
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Shape and Structural Optimization of Flapping Wings
… is performed using the modified Zimmerman method to describe the wing. A quasi-steady aerodynamics model is used to calculate the thrust and input power required during the flapping cycle. An assumed inflow model is derived based on lifting-line theory and is used to better approximate the …
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Numerical Simulations of the Aeroelastic Response of an Actively Controlled Flexible Wing
A numerical simulation for evaluating methods of predicting and controlling the response of an elastic wing in an airstream is discussed. The technique employed interactively and simultaneously solves for the response in the time domain by considering the air, wing, and controller as elements of a …
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Numerical Wing/Store Interaction Analysis of a Parametric F16 Wing
A new numerical methodology to examine fluid-structure interaction of a wing/pylon/store system has been developed. The aeroelastic equation of motion of the complete system is solved iteratively in the time domain using a two-entity numerical code comprised of ABAQUS/Standard and the …
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Modeling and Analysis for Optimization of Unsteady Aeroelastic Systems
… the complex physics and dynamics associated with unsteady aeroelastic systems is often attempted with high-fidelity numerical models. While these high-fidelity approaches are powerful in terms of capturing the main physical features, they may not discern the role of underlying phenomena that are …
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Time-Domain Simulations of Aerodynamic Forces on Three-Dimensional Configurations, Unstable Aeroelastic Responses, and Control by Neural Network Systems
… and mode shapes are found by the finite-element method. A general unsteady vortex-lattice method is used to provide aerodynamic forces. This method is verified by comparing the numerical solutions with the experimental results for several cases; and thereafter applied to several applications such …
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Neural-Network and Fuzzy-Logic Learning and Control of Linear and Nonlinear Dynamic Systems
… controller. LAMP is based on a source-panel method to model the flowfield around the ship, whereas the fins are modeled by a general unsteady vortex-lattice method. The ship is considered to be a rigid body and the complete equations of motion are integrated numerically in the time domain. …
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Numerical simulation of feedback control of aerodynamic configurations in steady and unsteady ground effects
… closely coupled lifting surfaces in steady and unsteady ground effects was developed. This model was coupled with the equations of motion to simulate aerodynamic-dynamic interaction. The resulting model was then coupled with a feedback-control law to form a general nonlinear unsteady numerical …
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Modeling Analysis and Control of Nonlinear Aeroelastic Systems
Airplane wings, turbine blades and other structures subjected to air or water flows, can undergo motions depending on their flexibility. As such, the performance of these systems depends strongly on their geometry and material properties. Of particular importance is the contribution of different …