Effect of anodes on wave loads of jacket members

ABSTRACT

Offshore structures such as jacket platforms have anodes fitted on their steel structural members to prevent corrosion. The anodes are projections on the surface of a tubular structural member and they increase the hydrodynamic forces and hydrodynamic coefficients of the tubular member. The effect of anodes on hydrodynamic forces and coefficients depends on several factors. The industrial practice to account for this effect is to multiply the total hydrodynamic force by a global factor, which may be conservative and uneconomical. The objective of this particular study is to determine the effect of location and orientation of anodes on wave loads and hydrodynamic coefficients of a cylinder, which have not been studied extensively to the authors’ best knowledge. The hydrodynamic forces and coefficients on a bare cylinder and a cylinder fitted with anodes were studied for regular waves of Keulegan-Carpenter (KC) number ranging from 0.42 to 1.91 in this experimental investigation.

KEYWORDS:

• Morison equation
• sacrificial anodes
• hydrodynamic coefficients
• wave loads
• least square method
• drag coefficient
• inertia coefficient
• cylinder

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Kasthuri Nallayarasu is pursuing her Master of Science degree under his guidance.

Rajamanickam Panneer Selvam is a Professor in the Department of Ocean Engineering, IIT Madras, India.