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 18 of 18 for “"Unsteady Forces"”.
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Computations of unsteady forces and moments for a transonic rotor with jet actuation
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1997.
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A design method for the prediction of unsteady forces on subsonic, axial gas-turbine blades
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1987.
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Measurement of unsteady forces on a circular cylinder in cross flow at subcritical Reynolds numbers
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1983.
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Reduction of unsteady underwater propeller forces via active tail articulation
… tail articulation as a means to reduce unsteady propeller forces and by extension, noise due to stator wake blade interaction. This study is experimental in nature and testing was completed in a closed-channel water tunnel at the Naval Undersea Warfare Center in Newport, RI. A …
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Steady and Unsteady Maneuvering Forces and Moments on Slender Bodies
Forces and moments have been measured on slender bodies in both static angle conditions as well as rapid time-dependent large amplitude maneuvers with the Dynamic Pitch Plunge Roll (DyPPiR) apparatus. <br /> <br /> Lateral and transversal forces as well as all three moments have been measured at …
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Wingsail design methodology and performance evaluation metrics for autonomous sailing
… which enables quantitative analysis of the unsteady forces affecting wingsail performance in realistic sailing conditions. The results highlight the limitations of traditional aerodynamic models due to unsteady flow conditions, and suggest that lighter wingsails designed with higher …
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Transient Study of Turbulent Flow and Particle Transport During Continuous Casting of Steel Slabs
… steel caster. The magnitudes of the steady and unsteady forces acting on the particles. The simulations found that only about 8% of the small particles (10 and 40 microns) were safely removed by the top surface slag layer. However, a higher removal fraction of about 12--70% was found for the …
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Wingsail Design Methodology and Performance Evaluation Metrics for Autonomous Sailing
… which enables quantitative analysis of the unsteady forces affecting wingsail performance in realistic sailing conditions. The results highlight the limitations of traditional aerodynamic models due to unsteady flow conditions, and suggest that lighter wingsails designed with higher …
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Parametric Viscous Analysis of Gust Interaction with Stationary and Elastically Mounted Airfoil
… interaction of SD7003 airfoil with non-uniform, unsteady incoming flow. The study is focused on the low-Re number unsteady flows typical of MAV applications in which a gust encounter can induce a particularly significant aerodynamic and aeroelastic response. Efficient source models are developed …
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Prediction of propulsor-induced maneuvering forces using a coupled viscous/potential-flow method for integrated propulsors
… develops a method to analyze the maneuvering forces on surfaced and underwater vehicles with complex propulsors. The analysis method is developed for general propellers yet has unique applicability to model highly contracting stern flows associated with integrated propulsors. Integrated …
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Exploring Complex Problems in Fluid Dynamics: from CFD to Experiments Leveraging ML
… environment are subject to large steady and unsteady forces, typically at high Reynolds number. Given the current limitations on CFD at high Reynolds number, and the high expense to conduct experiments at relevant scales, design is constrained by the limited available data, incomplete …
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Steady and unsteady waves generated by a moving body and multiple bodies
… uniform depth, there are circumstances when the unsteady effects can be significant. Among these examples are:;In practical operations, when a ship maneuvers in a port/harbour/lock environment. Under this circumstance, a ship is likely to travel in close proximity to waterway boundaries that have …
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Influence of aspect ratio on dynamic stall of a finite wing
The influence of aspect ratio, AR, on the unsteady aerodynamics of pitching wings was examined by comparing experimental performance, flow measurements, and computational results across a range of different AR wings. Performance measurements were acquired for three wings of AR = 3, 4, 5, and an …
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Flapping wings for dual aerial and aquatic propulsion
… design that can deliver the wide range of forces required. However, several bird species (including murres, puns, and other auks) successfully achieve dual aerial/aquatic propulsion using a single set of flapping wings, offering an existence proof for favorable ow physics. Flapping wings …
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Sound Radiated from Turbulent Flow over Two and Three-Dimensional Surface Discontinuities
… bubble upstream remains unaffected by it. The unsteady surface force in the lower half of the vertical face of the step was found to be independent of corner rounding. The force on the downstream surface shows similar character within the separation bubble for each rounding but decays faster …
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Unsteady Flow and Force Development in the case of a Circular Cylinder
… larger aircraft that can be subjected to highly unsteady flow fields. Sensing the flow and using predictive modelling to mitigate the unsteady forces shows potential, yet requires a detailed knowledge of the aerodynamic principles at play. This work is a fundamental study into the underlying …
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Unsteady hydrodynamics of ships moving in confined waterways
… there are still certain instances where unsteady effects cannot be ignored. For example: • Sudden changes of boundaries, such as the width and depth of the waterway. This may occur when ships navigate in port, harbor or lock environments. It will potentially increase the risk of …
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Three-Dimensional Unsteady Hydrodynamics of Tidal Turbines
… to the fluctuating loads that result from the unsteady flow, either from high-cycle fatigue or from extreme loading events exceeding the ultimate tensile strength of components. In this thesis, the problem of unsteady loading is addressed by identifying the shortcomings of the models currently …