Indian Journal of Science and Technology

Abstract

Objectives: To determine the hydrodynamic coefficients; drag (Cd) and inertia (Cm), for short-crested waves exerted on vertical cylinder. Methods/Statistical Analysis: An experimental study on hydrodynamic coefficients of the top-fitted vertical cylinder subjected to short-crested waves is presented. The model tests were carried out in the wave tank of Offshore Laboratory of University Technology PETRONAS, Malaysia. In this study, the model test was conducted by using two sets of vertical cylinder with diameter, 16 mm and 48 mm, which were subjected to four series of short-crested waves based on four different locations in Malaysian offshore region. The wave forces acting on the cylinder were recorded by using wave force sensor. The post processing data was carried out by considering The Least Square Method. The results were compared with the existing recommended hydrodynamic coefficients in the PETRONAS Technical Standard (PTS). Findings: The hydrodynamic coefficients for short-crested wave of a vertical cylinderwere obtained. The results showed that the experimental hydrodynamic coefficient values are 30 % to 45 % lower than the recommended hydrodynamic coefficients provided in PTS. Application/Improvements: The hydrodynamic coefficients values obtained from this experimental investigation have ensured the possibility of designing an economical and optimum design of offshore platforms could be achieved.

Keywords: Drag Coefficient, Inertia Coefficient ,Short-Crested Wave