Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 84 for “"vortex lattice"”.
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Winglet Performance Evaluation through the Vortex Lattice Method
… Falcon 10 small size business jet using the vortex lattice method solver program SURFACES© by GreatOWL Publishing. The winglet geometric parameters investigated were the winglet span, cant angle, sweep and taper ratio in terms of their influence on drag, range, fuel burn, as well as wing root …
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Wing Optimization Technique Based on Vortex Lattice Theory
… aerodynamic optimization technique based on vortex lattice theory is being proposed. The technique in this work will aim at optimizing the geometric parameters of a general wing with NACA 65-210 airfoil sections under a low speed aerodynamic regime. This will be completed by performing an …
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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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Visualization of the Vortex Lattice Dynamics in Superfluid Helium
We study the lattice structure and dynamics of the quantized vortices in superfluid helium-4 using a new rotating experiment. This setup includes control of the entire apparatus from the rotating frame, installation of a new EMCCD camera that allows for imaging of nanoscale tracer particles, and …
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Three dimensional flow analysis by the vortex-lattice method
A Vortex-Lattice Method (VLM) has been developed for the analysis of three-dimensional lifting bodies undergoing arbitrary motions. So far, the present method has been applied to thin surfaces in translational motion. Several cases were tested, such as rectangular, delta, sweptback and trapezoidal …
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High-field SANS studies of the vortex lattice in YBCO
… the first high-field structural study of the vortex lattice in YBa\(_2\)Cu\(_3\)O\(_7\). Small-angle neutron scattering was used to deduce the configuration of vortices in a twinned sample of YBa\(_2\)Cu\(_3\)O\(_7\) over the field range 1–11T applied parallel to the crystal c-axis. The …
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Numerically-based ducted propeller design using vortex lattice lifting line theory
This thesis used vortex lattice lifting line theory to model an axisymmetrical-ducted propeller with no gap between the duct and the propeller. The theory required to model the duct and its interaction with the propeller were discussed and implemented in Open-source Propeller Design and Analysis …
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Advances in ducted propulsor analysis using vortex-lattice lifting-surface techniques
Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997.
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Application of the vortex-lattice concept to flows with smooth- surface separation
A nonlinear three-dimensional vortex-lattice method which treats the steady separated flow over prolate bodies with open separation moving through an inviscid incompressible fluid is developed. The strength and position of the body wake are found as part of the solution. Specifically, flows with …
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An enhanced propeller design program based on propeller vortex lattice lifting line theory
… enhanced graphics capability. The MIT Propeller Vortex Lattice Lifting Line Program (PVL) is an executable file written in FORTRAN language and serves as a preliminary propeller design tool. In this thesis, PVL was rewritten in MATLAB® and presented with the GUIs. The enhancements were …
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A systematic investigation of the parameters affecting the accuracy of the vortex-lattice method
… the parameters affecting the accuracy of the vortex-lattice method when applied to a nonlinear lifting surface problem with leading edge separation. Among the factors investigated are the extensions of the bound vortex segments off the sharp edges of the wing, modifications of the Biot-Savart …
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Vortex Lattices in Rapidly Rotating Bose -Einstein Condensates: Modes, Elasticity, and Melting
"We approach the static elasticity of a vortex lattice using the elastohydrodyamic approach. We derive the elastic Green's function for the vortex lattice, and connect it to the lattice distortion in an inhomogeneous condensate. We find that the longitudinal elastic response of a vortex lattice is …
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Flight Dynamics and Maneuver Loads on a Commercial Aircraft with Discrete Source Damage
… that complicate the modeling. An extended vortex lattice code is used to model the quasi-steady aerodynamic forces. The vortex lattice method provides the force distribution which is not available elsewhere. Snapshots from the vortex lattice model are used to generate a reduced order model …
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Phase transitions and vortex dynamics in superconducting island arrays
… island arrays as a platform for studying vortex motion and quantum phase transitions. We investigate superconducting vortex dynamics and lattice structures in superconducting arrays by performing electrical transport measurements on Nb island arrays on Au at milli-kelvin temperatures and …
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A numerical model of unsteady, subsonic aeroelastic behavior
… 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 stall or vortex bursting near the wing. The fluid and the wing together are treated as a single dynamical system, and the …
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Numerical simulations of subsonic aeroelastic behavior and flutter suppression by active control
… to small disturbances or periodic motions. A vortex-lattice method is used to model the aerodynamics. This method accounts for nonlinear effects associated with high angles of attack, unsteady behavior, and deformations of the wing. The vortex-lattice method is valid as long as separation or …
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High frequency studies of the organic superconductor kappa-bis-ethylenedithio cuprous dicyanonitrobromide
We report measurements of the rf vortex penetration depth $\lambda$(B) of the organic compound, $\kappa$-ET$\sb2$Cu$\lbrack$N(CN)$\sb2\rbrack$Br as a function of temperature, magnetic field, and the angle made by the applied magnetic field with the ac-planes of the crystal. For$\rm\vec …
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Design and Development of Stability and Control Systems for Small, Deployable Aircraft
… pre-processor was developed to deflect them for vortex lattice computations. The accuracy of this method is compared against the conventional "control" vector method in subsequent testing. Wind tunnel testing was performed to evaluate longitudinal stability and controllability. Unpowered flight …
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