A Finite Element Model for Efficiency of a Moored Floating OWC Device in Regular Waves

2011 ◽  
Author(s):  
Jean-Roch Nader ◽  
Song-Ping Zhu ◽  
Paul Cooper ◽  
Brad Stappenbelt
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Wave Theory ◽  
Element Model ◽  
Energy Output ◽  
Chamber Pressure ◽  
Hydrodynamic Characteristics ◽  
Linear Wave ◽  
Regular Waves ◽  
Restoring Force

Hydrodynamic characteristics of floating OWC can be quite difficult to predict especially when a strong coupling is present between the chamber pressure and the device movements. Mooring properties, and air pressure inside the chamber can also considerably influence the motion of the device and therefore the energy output. A newly developed 3D finite element model based on the linear wave theory has been applied to a cylindrical type OWC device. The study focused principally on the effects of the mooring restoring force and pressure pneumatic damping in the chamber total volume flux and energy conversion of the device. Results show that properly chosen parameters could effectively increase the efficiency band width of such devices.

scholarly journals NEARSHORE CIRCULATIONS DUE TO WAVE INDUCED CURRENTS BY OFFSHORE BREAKWATER IN FINITE ELEMENTS

1986 ◽  
Vol 1 (20) ◽  
pp. 150
Author(s):  
Shinn-Chung Liang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Shallow Water Equation ◽  
Wave Theory ◽  
Element Model ◽  
Wave Pattern ◽  
Shore Protection ◽  
Radiation Stress ◽  
Induced Currents ◽  
Wave Induced

The objective of the present study is concerned with the numerical prediction of wave patterns and wave induced currents adjacent to a breakwater. The wave theory used is that of Berkhoff's (1972) mild slope wave equation with effects of diffraction, refraction and reflection described as Bettess, Liang and Bettess (1984). A finite element model is applied with appropriate boundary conditions. The singularity in the velocity at the tip of the breakwater is modelled effectively using the technique of Henshell and Shaw (1975), originally developed for elasticity. In the case of waves induced currents a potential representation of velocity in the fluid has be€>n used to derive a set of radiation stress expressions based on the theory of Longuet-Higgins (1964, 1970a,b), which are for an arbitrary wave pattern and the bottom variation. These expressions used account for the mean sea level and satisfy Mei's (1973) static balance of momentum flux. The radiation stress is applied to obtain forcing terms for use in a shallow water equation in conjunction with limiting ratio wave breaking where wave height, wave period, wave steepness and beach slope may be considered. Finally, an offshore breakwater on a beach for shore protection has been applied in a complete finite element model to predict both wave pattern and nearshore currents. Two angles of wave incidence are chosen. A series result has been produced.

scholarly journals Hull dynamics and strength of fast electric boat

2020 ◽  
Vol S-I (2) ◽  
pp. 224-229
Author(s):  
S. Ryabushkin ◽  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Strain State ◽  
Element Model ◽  
Regular Waves ◽  
High Compliance ◽  
Calculation Results ◽  
Response Amplitude Operators ◽  
Global And Local ◽  
Wave Induced

This paper identifies trim & draft parameters (spatial trimming) of a real fast boat with low-capacity motor, mostly running as a displacement vessel. The paper discusses various loading cases and calculates integral parameters in still water and regular waves (of various frequencies and incidence angles) for the ship at standstill and running at different speeds, also giving response-amplitude operators (RAOs) of motions and wave-induced moments. The study also gives calculation results for threedimensional fields of hydrostatic and hydrodynamic pressures and acceleration for further analysis of stress-strain state taking into account that finite-element model has no supports. High compliance (both global and local) of non-metal hull implies that the procedure suggested in this paper could be experimentally validated in future.

Finite Element Simulation of Tire-Rim Interface

1989 ◽  
Vol 17 (4) ◽  
pp. 305-325 ◽  
Author(s):  
N. T. Tseng ◽  
R. G. Pelle ◽  
J. P. Chang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Simulation ◽  
Contact Pressure ◽  
Element Model ◽  
Experimental Measurements ◽  
Inflation Pressure ◽  
Interference Fit ◽  
Element Simulation ◽  
Rubber Composite

Abstract A finite element model was developed to simulate the tire-rim interface. Elastomers were modeled by nonlinear incompressible elements, whereas plies were simulated by cord-rubber composite elements. Gap elements were used to simulate the opening between tire and rim at zero inflation pressure. This opening closed when the inflation pressure was increased gradually. The predicted distribution of contact pressure at the tire-rim interface agreed very well with the available experimental measurements. Several variations of the tire-rim interference fit were analyzed.

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

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