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Showing 1 to 14 of 14 for “"water entry"”.
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Cavity and projectile dynamics in intermediate Froude number water entry
Introduction: Water entry of projectiles has long been a topics of interest in both sciences and engineering. It began with Worthington, who in the late XIX century found experimentally that a cavity is being formed when a steel sphere enters water (Worthington and Cole (1895-1896)). As we know …
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Cavity dynamics of water entry for spheres and ballistic projectiles
… as these problems relate to the study of the water entry of mines and bullets, and the underwater launching of torpedos and missiles. Physical insight can also be applied to sports performance research relating to the water entry of athletes, reducing drag of swimmers near the free surface, …
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On falling spheres : the dynamics of water entry and descent along a flexible beam
… of the vertical impact of spheres on a water surface. Particular attention is given to characterizing the shape of the resulting air cavity in the limit where cavity collapse is strongly influenced by surface tension. A parameter study reveals the dependence of the cavity structure on …
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An Experimental Study of the Fluid- Structure Interactions of Water Entry of Compliant Structures
Water entry of compliant structures is a major area of interest within different fields of engineering. In the case of highly flexible panels, an application for this topic is on drag reduction due to shape reconfiguration of panels near the free surface to support further development of undulatory …
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Deterministic and stochastic modeling of the water entry and descent of three-dimensional cylindrical bodies
… mine-shaped object impacting the water surface from air and subsequently dropping through the water toward the sea bottom. This deterministic model, MINE6D, accounts for six-degree-of-freedom motions of the body. MINE6D allows for physics-based modeling of hydrodynamic effects due …
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An impulse framework for hydrodynamic force analysis : fish propulsion, water entry of spheres, and marine propellers
… to address the hydrodynamics of fish propulsion, water entry of spheres, and the offdesign performance of marine propellers. These seemingly-unrelated physics problems share a key common thread: The forces on these fish, spheres, and propellers can be modeled as the sum of the reaction to the rate …
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Hydroelasticity of High-Speed Planing Craft Subject to Slamming Events: An Experimental and Numerical Investigation of Wedge Water Entry
… craft operating in waves are subject to frequent water impact, or slamming, as a portion or whole of the craft exits the water and re-enters at high velocity. The global load induced by slamming can cause fatigue-related damages to structures. The local slamming can cause local damage to …
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Crossing the Air-Water Interface: Inspiration from Nature
… aims to contribute toward the understanding of water-entry and -exit behaviors in nature. Since water is nearly a thousand times denser than air, transitioning between the two mediums is often associated with significant changes in force. Three topics with implications in water-entry are …
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On the impact of arbitrary two-dimensional sections
When an object drops into the water a slamming load with high pressure on the body happens. Such an impact force often causes serious structure damage to the ships and offshore structures. The study of the water-entry impact problem is thus of fundamental interest and practical significance in …
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Slamming of High Speed Craft: A Parametric Study of Severe Cases
… to be an intermediate step between vertical water entry tests of a wedge and a traditional tow tank experiment of a planning hullform in waves. This allowed a deeper study of the hydrodynamic loads that occur during slamming. A planing hull model was subjected to controlled motions in the …
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Development and Validation of Fluid-Structure Interaction in Aircraft Crashworthiness Studies
… composite undercarriage was evaluated during water ditching. The severe impact of aircraft ditching is dynamic and nonlinear in nature; the goal of this work to develop a methodology that not only captures the structural response of the aircraft, but also the fluidic behavior of the water. …
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Fluid Dynamics in Liquid Entry and Exit
… in animal behaviors like the locomotion of water-walking animals, the plunge-diving of birds, and the jumping out of water of marine creatures. Depending on the moving direction of a solid, such diverse phenomena can be classified into two categories; liquid-entry and liquid-exit. …
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Slamming of High-Speed Craft: A Machine Learning and Parametric Study of Slamming Events
… through a controlled motion slam into calm water. To provide a baseline to compare data from future controlled motion experiments to, a model drop experiment was completed to characterize the relationships of impact velocity and trim to slamming event severity. During this experiment, the …
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Free Surface Penetration of Inverted Right Circular Cones at Low Froude Number
In this thesis the impact of inverted cones on a liquid surface is studied. It is known that with the right combination of velocity, geometry, and surface treatment, a cavity of air can be formed behind an impacting body and extended for a considerable distance. Other investigators have shown that …