Linear vs non-linear analysis on self-induced vibration of OTEC cold water pipe due to internal flow

• DOI: 10.1016/j.apor.2021.102610
• Publication Date: 2021-03-21T10:26:02Z
• Authors: Ristiyanto Adiputra; Tomoaki Utsunomiya
• Keywords: Morison equation; Added mass; Critical ionization velocity

This paper presents analytical and numerical analyses on self-induced vibration of Ocean Thermal Energy Conversion (OTEC) Cold Water Pipe (CWP) for a 100 MW-net OTEC power plant. The CWP is described as vertically-hanged, top-tensioned riser subjected to internal flow effect (IFE) ambient fluid effects (added mass drag force). In the analysis, two definitions force equation in frequency-domain term time-domain are considered yielding linear differential non-linear equation. stability assessed by discretizing equations using Frobenius method Galerkin Method then plotting its eigenfrequencies or eigenvalues an Argand diagram. Separately, fully-coupled fluid-structure interaction carried out simulation particular cases. scantlings chosen from available size Fiber Reinforced Plastic (FRP) pipe manufacturer varied accordingly future production capacity development. pinned at top mounted bottom. Results indicate that predicted critical velocity time domain averagely 20% higher compared frequency domain. clump weight more significant light material with relatively high-density material.