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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 24 for “"Body of revolution"”.
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Finite difference techniques for body of revolution radar cross section
Although a number of radar cross section prediction techniques have been developed which exploit body of revolution symmetry, the use of finite-difference techniques with these geometries has not been throughly explored. This thesis investigates several finite-difference approaches which vary both …
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Computational Simulations of a Non-body of Revolution Ellipsoidal Model Utilizing RANS
The ability of Reynolds Averaged Navier Stokes (RANS) models to predict the characteristics of a non-Body of Revolution (non-BOR) Ellipsoidal model is studied to establish the feasibility of utilizing RANS as a non-BOR concept design tool. Data unable to be obtained experimentally, such as …
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Solution Of Electromagnetic Scattering Parameters And Radiation Patterns Of Arbitrary Body Of Revolution Radiators
… parameters and the radiation field intensities of arbitrary Body of Revolution (BOR) radiators consisting of impenetrable media is explored through derived components of modal analysis and the method of moments (MoM). Modal excitation is utilized to excite the structural feed; allowing for a …
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Force and moment on a slender body of revolution moving in water of finite depth.
Massachusetts Institute of Technology. Dept. of Naval Architecture and Marine Engineering. Thesis. 1970. M.S.
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The dynamic stresses generated in a finite elastic body of revolution by longitudinal impact with a rigid wall
… statements concerning phase and group velocities of stress waves propagating in elastic media where at least one dimension is infinite are valuable for separating the distinct characteristics of the various operating phenomena. The problem of impact of a finite body, however, is so greatly …
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Optimization parameters for a membrane polygonal body of revolution with zero meridional stress and its application to parachutes
A polygonal body of revolution consisting of discrete meridional members joined by regular polygons is optimized for maximum drag and drag coefficient. The meridional, or primary members, carryall of the radial loads and the membrane structure transfers applied pressure loads to the primary …
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Application of integral equation and finite difference methods to electromagnetic scattering by two-dimensional and body-of-revolution geometries
The theoretical and numerical studies of electromagnetic scattering and radiation from perfectly conducting as well as dielectric bodies are of great importance in the design of various systems, such as airborne targets and antennas. This thesis is an attempt to investigate integral equation and …
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Finite Element Method for Electromagnetic Scattering and Radiation From Complex Axisymmetric Structures
… is also developed to compute scattering from a body of revolution (BOR) with appendages. First, the FEM is used to compute the scattering from the BOR with the appendages removed. The incident field on the appendages in the presence of the BOR is then known, and the method of moments (MoM) with …
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Stress Interference in Axisymmetric Torsion of a Transversely Isotropic Body (Elasticity, Solid Mechanics, Anisotropic, Stress Concentration)
An unbounded transversely isotropic body of revolution containing two spheroidal cavities is subjected to torsion about its axis of elastic symmetry, which coincides with its axis of revolution. At large distances from the cavities the elastic field approaches the Saint-Venant solution for the …
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Radar scattering from bodies of revolution using an efficient partial differential equation algorithm
… equation techniques for solving the problem of electromagnetic scattering by a three-dimensional body of revolution are discussed. The unknowns used do not obey the scalar Helmholtz equation. Thus, neither the Mur nor the Bayliss-Turkel boundary condition can be used. Therefore, a boundary …
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The Impact of Three Dimensional Flow Anisotropy and Transients on Turbulence Ingestion Noise in Open Rotors
The effect of flow anisotropy and three dimensional separation on the turbulent structure and radiated turbulence ingestion noise of a rotor in two experimental configurations is studied. The first consists of a non-axisymmetric boundary layer wake ingested by a rotor mounted at the aft of a body …
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Retrieval of equivalent currents by the use of an integral representation and the extinction theorem --- radome applications
The aim of this thesis is to solve an inverse source problem. The approach is based on an integral representation together with the extinction theorem. Both a scalar and a full-wave integral representation are implemented and solved by a Method of Moment procedure. The body of revolution enables …
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Afterbody drag prediction for conceptual aircraft design
… This versatility is increasing the afterbody complexity and the difficulty in afterbody drag prediction. This thesis documents a computationally inexpensive method for estimating the afterbody drag of aircraft during the conceptual design stage. The design and creation of a new hybrid …
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An experimental investigation into the components of ship resistance
… experimental investigation into the components of ship resistance. The traditional Froude method of scaling is investigated with reference to the measurement of skin friction and viscous pressure resistance. A literature review is given on the theoretical background and experimental measurement …
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Steady and Unsteady Maneuvering Forces and Moments on Slender Bodies
… moments have been measured at static angles of attack and sideslip and unsteady pitch ramp maneuvers at a fixed point of rotation at the quarter length of the body. The two bodies are the DARPA Suboff generic submarine shape and a non-Body-of-Revolution scalene ellipsoid with a constant …
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Creep buckling of shells of revolution loaded under uniform external pressure
… is undertaken into the creep instability of two common shells of revolution, the infinitely long cylinder and the complete sphere. The linear and non-linear visco-elastic material idealizations are used in the various theoretical procedures. The critical buckling time is greatly influenced …
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Skin Friction and Cross-flow Separation on an Ellipsoidal Body During Constant Yaw Turns and a Pitch-up Maneuver with Roll Oscillation
… and cross-flow separation location on a non-body-of-revolution (non-BOR) ellipsoidal model performing constant-yaw turns and a pitch-up maneuver, each with roll oscillation were studied for the first time. The detailed, low uncertainty, flow topology data provide an extensive experimental …
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Method of Moment Analysis of Partially Shielded Chiral Bodies of Revolution
<p>A chiral body of revolution (BOR) which is partially covered by a thin conducting shield is analyzed using the method of moments (MOM). The axisymmetric system is excited by a plane wave. The total internal fields and the far scattered fields are computed. The problem is solved using the surface …
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The Space-time Structure of an Axisymmetric Turbulent Boundary Layer Ingested by a Rotor
… turbulence ingestion noise. The combined effect of lateral curvature and streamwise pressure gradient are examined on the mean flow, turbulence structure, velocity correlations and wall pressure fluctuations. Additionally, the upstream influence of a rotor operating in this flow is examined to …
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The Adaptive Cross Approximation Algorithm Applied to Electromagnetic Scattering by Bodies of Revolution
… solved numerically by approaches like the method of moments or the Nystrom method. These approaches yield a dense system of linear equations. The coefficient matrix must be computed and stored, which requires a great deal of computational resources. The adaptive cross approximation (ACA) algorithm …
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