Vortex Induced Vibration of Cold Water Pipe of OTEC

Abstract

Ocean Thermal Energy Conversion (OTEC) is a process that can produce electricity by using the temperature difference between deep cold around 28 degree Celsius ocean water and warm tropical surface waters around 6 degree Celsius. Indonesia have many potential locations to build OTEC, among them is in Sumatera Utara, Bali, Flores Sea, Makassar Strait. The problem with pipes in the ocean is that as the ocean water flows past the pipe with a certain current velocity, a phenomenon called vortex-induced vibrations (VIV) might occur, potentially leading to very large oscillations. As the OTEC cold water pipe has unusual large diameter, the fluid will flow at unusual high Reynolds numbers. This paper investigates the effect flow past the pipe with different velocities and large diameters of pipe. The location is in Makassar strait and the velocity is obtained by data from previous researcher based on deep water is 0.8 m/s, 0.62 m/s, 0.46 m/s , 0.35 m/s , 0.28 m/s. The large diameter of pipe is obtained used OTEC Pro Simulation based on population in Karampuang Island at the Makassar strait is 4m and 3m diameter of pipe. The result obtained from numerical simulation used ANSYS FLUENT