Hydrodynamic forces on barnacles: Implications on detachment from fouling‐release surfaces

Abstract

Concern over the environmental impact of traditional biocide‐containing antifouling formulations has led to the development of non‐toxic, fouling‐release coatings. An “ideal”; fouling‐release surface for a ship is one that reduces the tenacity of biofouling to a point that hydrodynamic self‐cleaning occurs under normal operating conditions. In order to address the feasibility of designing such a surface, an understanding of the relationship between the hydro‐dynamic forces and the strength of adhesion of the organism to the substrate is needed. This paper presents the results of an experimental investigation to measure the hydrodynamic lift and drag of an acorn barnacle (Balanus eburneus) attached to an instrumented foil. The results are used to generate a model of the tensile and shear stresses at the base of the barnacle, as a function of the water velocity. Predictions of the maximum barnacle adhesion strength in shear and tension that will allow detachment at operational speeds are offered.

Key words:

• hydrodynamic forces
• lift
• drag
• Balanus eburneus
• fouling‐release coatings

Notes

Corresponding author. Current address: Division of Engineering R&D, Harbor Branch Oceanographic Institution, 5600 US1 North, Fort Pierce, FL 34946, USA; fax: [phone]; e‐mail: [email protected]