Numerical Study on Wave Run-up of a Circular Cylinder with Various Diffraction Parameters and Body Drafts

Abstract

Wave run-up is an important phenomenon that should be considered in ocean structure design. In this study, the wave run-up of a surface-piercing circular cylinder was calculated in the time domain using the three-dimensional linear and fully nonlinear numerical wave tank (NWT) techniques. The NWT was based on the boundary element method and the mixed Eulerian and Lagrangian method. Stokes second-order waves were applied to evaluate the effect of the nonlinear waves on wave run-up, and an artificial damping zone was adopted to reduce the amount of reflected and re-reflected waves from the sidewall of the NWT. Parametric studies were conducted to determine the effect of wavelength, wave steepness, and the draft of the cylinder on the wave run-up of the cylinder. The maximum wave run-up value occurred at 0°, which was in front of the cylinder, and the minimum value occurred near the circumferential angle of 135°. As the diffraction parameter increased, the wave run-up increased up to 1.7 times the wave height. Furthermore, the wave run-up was 4% higher than the linear wave when the wave steepness was 1/35. In particular, the crest height of the wave run-up increased by 8%.

Two-Way Coupling Simulation of Fluid-Multibody Dynamics for Estimating Power Generation Performance of Point Absorber Wave Energy Converters

“…Reference source not found., in the process of representing a plate thinner than the particle size or the slope of a float by a regular arrangement of particles, distortion may have occurred compared to the actual shape, which may have affected the response characteristics of the object motions in waves. In addition, because the thin plate was expressed with relatively large particle sizes and the mass was increased to adjust for the resulting buoyancy force, this The velocity-based damping force, which is a constraint condition for modeling the PTO system, can be expressed by Equation (11): Based on this equation, the instantaneous absorbed power with time can be calculated, as shown in Equation (12), and the final averaged absorbed power is calculated using Equation (13).…”

“…In addition, various numerical studies [12,13] have been conducted for the efficient design of WEC considering a significantly complex problem requiring multiphysics simulation (hydrodynamics, multibody dynamics, power take-off system analysis, control, etc.) encompassing different fields.…”

Fracture Estimation in Ship Collision Analysis—Strain Rate and Thermal Softening Effects

“…Assessments of the resistance of ship and offshore structural components subjected to extreme and accidental loadings, such as collision and grounding [1], explosion and blast accompanied with fire [2,3], and slamming [4], are impact engineering problems. Under impact loads, the structural response may differ considerably from that under a quasi-static load [5] because the mechanical properties are affected significantly by the loading speed and resulting strain rates.…”