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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 96 for “"added mass"”.
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Added Mass and Vortical Impulse: Theory and Experiment
… decomposition of aerodynamic force into added-mass and circulatory components is derived under the assumption of inviscid flow. In the present thesis, this decomposition is shown to be valid for viscous flows. The classical added-mass force, derived using (acyclic) potential flow theory, …
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Shape change for global vorticity shedding and added mass energy recovery
… from the wake back to the body in the case of added mass energy recovery. Global vorticity shedding occurs when an object rapidly vanishes from the fluid. A rapid retraction is an approximation of a disappearing object, and as a result both the added mass energy as well as the entirety of the …
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Hydrodynamic added mass determination and attitude estimation of the Seahog - a remotely-operated underwater vehicle
… velocity. This resistive force is known as the added mass. Added mass covers both the translational mass and the rotational moment of inertia. This can be viewed as the volume of fluid that a vehicle has to move aside while in motion. A Simulink-based simulation model of the Seahog had been …
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Modeling the effects of Reynolds number and added mass on the vortex-induced vibration of drilling risers
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000.
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The influence of added mass on the natural vibrations and impulse response of long, thin cylindrical shells
… of a thin circular cylinder containing an added line mass. The solution for a uniform cylinder is derived by taking the added mass to be zero. Numerical calculations of the frequencies and mode shapes for several of the lower modes are presented in graphical form for various values of the …
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A GENERALIZED CONSERVATION OF CIRCULATION MODEL IN VORTICITY DYNAMICS AND ITS APPLICATION TO VORTEX CALCULATION METHOD
… The GCCM is then extended to study the added mass of an accelerating circular cylinder in fluid, which is of practical importance. However at present, there is no satisfactory mathematical description of the added mass due to the lack of an exact physical definition. In this thesis, the …
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Unsteady Aerodynamics of Wing-Gust Encounters
… transverse to the lifting surfaces can cause massive changes to the angle of incidence, fluctuations in lift and drag, and result in flight instability. This may be catastrophic for small drones, and hazardous for larger aircraft during take-off and landing. Onboard gust sensing and …
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Calibration of an arch dam model by the finite element method using ambient vibration testing
… It is from the same study that the Westergaard added mass concept was born which says that the interacting water mass can simply be added to the dam wall mass, a procedure from which the extraction of the dynamic properties can ensue as normal. This added mass formulation was derived on a basis …
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Numerical and experimental analysis of initial water impact of an air-dropped REMUS AUV
… surface of the object. The shape-dependent added-mass coefficients express the fluid forces integrated over the body, and thus physically represent the additional inertia of water accelerated with fie body. The field of hydrodynamic impact has been primarily concerned with estimating the …
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Numerical and experimental analysis of initial water impact of an air-dropped REMUS AUV
… surface of the object. The shape-dependent added-mass coefficients express the fluid forces integrated over the body, and thus physically represent the additional inertia of water accelerated with the body. The field of hydrodynamic impact has been primarily concerned with estimating the …
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Virtual Planar Motion Mechanism Testing of 8:1 Spheroids
PMM testing is a method used to identify the added mass and damping coefficients used in the equations of motion of a vehicle by attempting to decouple the forces on a body due to velocity and acceleration as a result of creating "hydrodynamically pure" velocities and accelerations. This makes it …
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Effect of traveling waves on Vortex-Induced Vibration of long flexible cylinders
… of the waves, the response amplitude and the added mass coefficient. The mean added mass coefficient for the bare cylinder is shown to be approximately one and the maximum response amplitude is found to be approximately one diameter. A Green's function, response prediction method, is …
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A frequency domain strip theory applied to the seakeeping of the Zumwalt-Class destroyer
… frequency range. SMA calculates sectional added mass and damping coefficients first. Then, it calculates excitation forces and moments acting on a ship advancing at constant forward speed with arbitrary heading for sway, heave, roll, pitch and yaw modes of motion. Finally, SMA evaluates …
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Time domain simulation of hydroelastic response of ships in large amplitude waves
… hydrodynamic forces are due to changes in added mass and damping coefficients, as well as restoring and incident wave forces, all evaluated over the instantaneous wetted surface. Non-linear forces due to slamming (bottom impact and flare) and green water (treated in a quasi-static manner) …
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ΔΥΝΑΜΙΚΗ ΤΩΝ ΡΗΓΜΑΤΩΜΕΝΩΝ ΔΟΚΩΝ ΣΤΟ ΝΕΡΟ
… THE CONCEPT OF CRACKED NODE. FOR THE FLUID THE ADDED MASS MATRIX IS COMPUTED BY THE BOUNDARY ELEMENT METHOD OF SOURCES. ALSO WAS COMPUTED, THE LOCAL COMPLIANCE COEFFICIENT IN BENDING, FOR HOLLOW ORTHOGONAL BEAMS.
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WEAKLY NONLINEAR DYNAMIC ANALYSIS OF FLOATING BODIES IN WAVES
… to evaluate the Froude-Krylov force and the added mass and damping forces of the three dimensional floating body. The effects of instantaneous wetted surface and large motion of each strip are also considered. In the study, it is not necessary to limit the motions of the floating body to …
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Hydrodynamic performance of multi-component structures in oscillatory flow, from blow-out preventer to dual Cylinder interference
… recommended modeling coefficients that the added mass coefficient Cm and the drag coefficient Cd both have a much larger value than the industrial model provided, and they vary significantly as the function of the key parameters. An equivalent box model was built and tested to capture the …
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Sea-state interaction based dynamic model of the Liquid Robotics' Wave Glider: Modelling and control of a hybrid multi-body vessel
… from a SolidWorks model of the system, and added mass components are determined from empirical data. Finally, the dynamic model is verified for a given sea state and multiple sea states are tested to investigate the effect on the model’s performance. The developed Wave Glider model is shown …
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Exploring the Limits of Boundary Element Methods for Wave Energy Converter Hydrodynamics
… (WECs). The representations– excitation, added mass, and radiation damping in up to six degrees of freedom– define and scale the forces in the equation of motion for these devices, and can be used in time-domain modeling tools to predict the behavior of the system in response to waves. It …
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The Structural Response of a Frame-Membrane Lunar Habitat Subjected to Impact and Thermal Loads
… loading and incorporates the effects of the added mass due to the regolith cover and the stress stiffening from the internal pressurization. The impact loading was analytically determined considering a moving projectile, for example space debris, hitting the midpoint of a frame member at the …
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