An experimental investigation of the effect of foul release coating application on performance, noise and cavitation characteristics of marine propellers

A number of ship propellers have been coated with anti-fouling paint, namely foul release, to improve propeller efficiency as a result of dramatic increases in fuel prices. This has recently been coupled with tougher environmental regulations forcing the shipping community to review their anti-fouling policies. With the introduction of a new generation antifouling coatings, it is now possible to apply these coatings not only to keeping the hull free from bio-fouling, but also on propellers to improve their performance. Within the above context an investigation into effect of the coatings on the hydrodynamic performances of marine propellers were carried out. This paper reports on effects of foul release coatings on the efficiency, cavitation and noise characteristics of a marine propeller at model scale. The paper includes the details of these tests conducted in Emerson Cavitation Tunnel of Newcastle University and discusses paint application, surface characterisation issues and analysis of test results for coated and uncoated conditions. The results indicated that coating may not cause any performance reduction when applied correctly. Cavitation development on blades was slightly reduced by the coating and the coating of blades reduced noise level in non-cavitating condition, but increased in developed cavitation condition, requiring further investigation.