Problemi lineari e non lineari di flusso intorno ad ostacoli

We discuss the problem of the steady two-dimensional flow past fixed disturbances in an open channel of finite depth. We consider different types of obstacles, like submerged or surface-piercing bodies, and localized perturbations of a horizontal bottom; recent results on unique solvability of the linear problem and rigorous proofs of solvability of the non linear, free boundary problem are reviewed

Features of nonlinear wave-wave and wave-body interactions

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2000.Includes bibliographical references (leaves 295-302).Although nonlinear water waves have been the subject of decades of research, there are many problems that remain unsolved, especially in the cases when one or more of the following factors are involved: high-order nonlinear effects, moving boundaries, wavestructure interactions and complicated geometries. In this dissertation, a high-order spectral-element (HOSE) method is developed to investigate problems about nonlinear waves. An exponentially converging algorithm, it is able to be applied to solve nonlinear interactions between waves and submerged or surface-piercing bodies with high-order nonlinear effects. The HOSE method is applied to investigate dynamics of nonlinear waves and their interactions with obstacles. We first implement it to calculate the hydrodynamic forces and moments on a fixed underwater spheroid, with uniform current, different angles of attack and finite water depth included in the study. Extending this study to wave interaction with tethered bodies, we create an efficient simulation capability of moored buoys. Coupling the HOSE method with a robust implicit finite-difference solver of highly-extensible cables, our results show chaotic buoy motions and the ability for short wave generation. We then focus our attention on the free-surface patterns caused by nonlinear wave-wave and wave-body interactions. Starting with a two-dimensional canonical problem about the wave diffraction and radiation of a submerged circular cylinder, numerical evidences are obtained to corroborate that, for a fixed cylinder, a cylinder undergoing forced circular motion, or free to respond to incident waves, the progressive disturbances are in one direction only. The three-dimensional wave-wave interactions are studied. It is proved both analytically and numerically that new propagating waves could be generated by the resonant interactions between Kelvin ship waves and ambient waves. Another consequence of resonant wave-wave interactions is the instability of free-surface waves. In this dissertation, the three-dimensional unstable modes of plane standing waves and standing waves in a circular basin are identified numerically and then confirmed analytically. These investigations cover a large variety of nonlinear-wave problems and prove that the HOSE method is an efficient tool in studying scientific or practical problems.by Qiang Zhu.Ph.D

I. Regular and chaotic motions in a wave tank, II, interactions between a free surface and a shed vortex sheet

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1992.Includes bibliographical references (leaves 142-143).by Wu-ting Tsai.Ph.D

Study on the Mechanical Properties of Carbon Nanotube Coated‒Fiber Multi-Scale (CCFM) Hybrid Composites

L'abstract è presente nell'allegato / the abstract is in the attachmen

Numerical Boundary Condition Procedures

Topics include numerical procedures for treating inflow and outflow boundaries, steady and unsteady discontinuous surfaces, far field boundaries, and multiblock grids. In addition, the effects of numerical boundary approximations on stability, accuracy, and convergence rate of the numerical solution are discussed

15th Conference on Dynamical Systems Theory and Applications DSTA 2019 ABSTRACTS

From Preface: This is the fifteen time when the conference „Dynamical Systems – Theory and Applications” gathers a numerous group of outstanding scientists and engineers, who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without a great effort of the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and the Ministry of Science and Higher Education. It is a great pleasure that our invitation has been accepted by so many people, including good colleagues and friends as well as a large group of researchers and scientists, who decided to participate in the conference for the first time. With proud and satisfaction we welcome nearly 255 persons from 47 countries all over the world. They decided to share the results of their research and many years experiences in the discipline of dynamical systems by submitting many very interesting papers. This booklet contains a collection of 338 abstracts, which have gained the acceptance of referees and have been qualified for publication in the conference edited books.Technical editor and cover design: Kaźmierczak, MarekCover design: Ogińska, Ewelina; Kaźmierczak, Mare

A cumulative index to the 1973 issues of Aeronautical engineering: A special bibliography

This publication is a cumulative index to the abstracts contained in NASA SP-7037 (28) through NASA SP-7037 (39) of Aeronautical Engineering: A Special Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes

Aeronautical engineering: A continuing bibliography with indexes (supplement 276)

This bibliography lists 705 reports, articles, and other documents introduced into the NASA scientific and technical information system in Feb. 1992. Subject coverage includes: design, construction, and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Solidification and Gravity VII

International audienc