WAVE TRANSMISSION AND REFLECTION BY TREES AND POROUS STRUCTURES

Laboratory experiments were performed to study wave transmission and wave reflection capacity of circular cylinders, modeling trees and porous structures near the coast as coastal protection from wind waves and tsunamis. The energy dissipated in the array of circular cylinders was evaluated by measuring the drag forces acting on them and wave particle velocities of incident waves. The drag forces acting on a circular cylinder are measured by using a multi component load cell. The wave particle velocities are measured by using a Laser Doppler anemometer. A theoretical and numerical analysis based on application of the continuity and energy equations to flow through the rows of circular cylinders were made to evaluate wave transmission and wave reflection capacity in the array of circular cylinders. The reflection coefficient K-r is significant for large value of the ratio of the circular cylinders area to the unit bed area in the array of circular cylinders.