Optimum design of Wave Absorber in Various Sinusoidal Propagating Wave

다국어 초록 (Multilingual Abstract)

Since there has been a rapid progress to understand the dynamics of the coastal wave under a sloping-wall-type breakwater, we undertake to simulate the coastal waves and wave absorbers in a lab-scale wave flume. The study is aiming to observe and optimize a similar ocean environment and to reduce the wall reflection in the wave flume. In order to generate the ocean waves in the wave flume, the combination of the flat-type wave generator and wave absorbers is installed at the channel. Two probes for measuring the wave heights (i.e., level gauges) are used to observe the temporal variation of wave surface as well as the phase difference and the maximum (crest)/minimum (trough) points between the propagating waves. In order to optimize the shape and size of propagating waves, several absorption methods are proposed ?vertical-porous-plates absorber, horizontal punching plates absorber, sloping-wall-type wave absorber and active wave absorption, but for the better option of the propagating waves, the sloping-wall-type wave absorbers are chosen and tested in terms of the constitutive filling materials and the location and shape of the frame. This paper also focuses on the theoretical prediction of the wave surface separating them into incident and reflective components. In the result, it clearly shows that the wave absorber with hard filling material has better performance than that of soft material; i.e., wave absorber can be a strong sink to control the energy of the coming wave. In addition, the larger wave absorber becomes, the lower the reflectance be since the larger volume can remove the on-coming wave energy better. Therefore, given that the same condition of absorber is provided, the reflectance becomes bigger as the wave period is longer. Finally, the reflectance of wave would be controlled under 0.1 in this study so that the wave flume would be applied for simulating the offshore environment.

목차 (Table of Contents)

• Abstract
• 1. Introduction
• 2. Design of laboratory experiments
• 3. Results and Discussion
• 4. Conclusion
• References