THE EFFECT OF CHANGE IN SEA DEPTH TO TRANSMISSION AND REFLECTION WAVES

• Main Author: Darmawan, Kevin
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/53648
• Institution: Institut Teknologi Bandung

The length of the coastline in Indonesia is one of the longest in the world. In coastal areas, there are many phenomena related to ocean waves, such as abrasion by sea wave, sea tides, tsunami, the principle of a waterbreak, etc. This research focuses on the transmission and reflection of waves. Transmission wave occurs because wave propagation is forwarded into areas with different ocean depths, dan reflection wave occurs because part of the wave energy is reflected back against the transmission wave and inflicts a superposition wave. One of the propagation wave phenomena is shoaling. The shoaling phenomenon occurs because the amplitude of wave has increased due to the movement of the wave entering shallower waters. The subject of this research is transmission and reflection waves where the waves propagate to areas with different depths, from deep waters to shallower waters. In this section, it will be divided into two studies, namely transmission and reflection waves in areas of different depths without a transition region and the other one with a transition region. Transmission and reflection waves will be determined by the shallow water equation. There are two methods used, analytic derivation and numerical simulation. Analytical derivation will be solved by deriving the wave equations and shallow water equations. Numerical simulations will be solved by the numerical method, namely the Staggered Grid. Both methods will be used for both cases with transition region and without transition region. The numerical method will be compared with the analytical derivation. From that comparison, the error obtained is small enough such that the method is suitable for simulating this case. In the case without the transition region, from the analytical and numerical results, it is found that when the depth in the shallow area decreases, the height of the transmission and reflection waves gets bigger. In case that involving a transition area, the effect of the transition area width and shallow water depth on the analytical transmission coefficient will be seen. The transmission coefficient will be compared to the value of the transmission coefficient without transition area and the value of Green's Law. If the width of the transition area increased, then the transmission coefficient is closer to the value of Green's Law. If the width of the transition area decreased, then the transmission coefficient is closer to the value of the transmission coefficient without the transition region.