Towards a Computational Multiphysics Framework for Modeling Antibiofouling Processes

Author(s):  
Athanasios Iliopoulos ◽  
John G. Michopoulos ◽  
Virginia DeGiorgi ◽  
Steven Policastro

Biofouling is a process of major concern on naval vessels because it considerably affects their performance, maintenance and operational costs due to the fact that induces an increased hydrodynamic drag that leads to higher fuel consumption that in turn demands expensive cleaning procedures. A possible antibiofouling system can be designed by enhancing an existing impressed current cathodic protection system and taking advantage of the chlorine oxidants produced during its operation. In this work we present a design methodology for such a system, together with the associated multiphysics formulation framework based on a coupled chemical reactions — electric currents, species mass transport and electromigration model. This framework predicts the spatio-temporal distributions of the Chlorine species concentration that tend to inhibit the biofouling formations. We also demonstrate the applicability of the computational framework on a number of platforms ranging from simple panels up to a full scale boat. The computational results are compared with the actual field experiments.

CORROSION ◽  
1959 ◽  
Vol 15 (7) ◽  
pp. 41-46 ◽  
Author(s):  
HARRY J. KEELING

Abstract Details are presented on the planning, design and installation of corrosion protection facilities to provide 100-year design life for a 7-mile, 22-inch steel pipe sewer outfall, the outer end of which is in ocean water 340 feet deep. The outfall serves the sewerage systems of Los Angeles and 16 other adjacent municipalities. An impressed current cathodic protection system is used to protect the exterior of the pipe which is wrapped with a multiple-layer coal tar coating reinforced with glass fiber with bonded impregnated asbestos felt shield. A reinforced pneumatically applied cement mortar jacket provides negative buoyancy. Interior is protected by centrifugally-spun mortar lining with epoxy sleeves at welded tie-in joints. Because of the depth of water in which the pipe was to be placed several novel features were necessary. Cathodic protection was applied continuously during installation by the use of zinc anodes. This system was monitored to detect any serious coating holiday before the pipe was laid in deep water. Permanent test leads also were attached to the pipe so performance of the impressed current system could be checked, continuously. After 1½ years' operation there has been very little change in effective coating resistance, a pipe potential of —1.05 volts versus a copper/copper sulfate electrode being maintained with consumption of about 150 ma. 5.2.3


1984 ◽  
Vol 24 (1) ◽  
pp. 160
Author(s):  
A. J. Lees

The Barrow Island oil field, with an area of about one hundred square kilometres containing over six hundred wells, presents an engineering challenge of vast magnitude in the protection of investment in the wells and their casings against the destructive process of corrosion. The growing incidence of casings leaks and escalation in the costs of repairing externally corroded casings provided the impetus for pilot scheme studies and subsequent design and installation of an impressed current cathodic protection system on a scale not previously undertaken in Australia.Data obtained from pilot scheme tests carried out in the latter half of 1979 established the basis of a feasible design. Detailed design and installation through 1980-81 was followed by commissioning of the first area of the system early in 1982.Design of the cathodic protection system was tailored to the local field conditions; the design was modified when necessary as installation and commissioning difficulties arose. Several minor operational problems encountered to date are still to be resolved.The total initial outlay of $5.7 million should result in minimum cumulative savings in well casing repair costs of $15 million over the next 15 years.


CORROSION ◽  
1957 ◽  
Vol 13 (2) ◽  
pp. 52-54 ◽  
Author(s):  
E. E. NELSON

Abstract A cathodic protection system using platinum-clad copper anodes on neoprene shields was installed on a fleet-type submarine. Current was supplied from a rectifier to 11 anodes distributed over the hull, the potential being monitored by 13 silver-silver chloride electrodes at selected locations. The system was operated for a ten-month period of active duty after which inspection on a marine railway showed the hull to be in excellent condition with the vinyl paint functioning well. Three of the anodes were damaged but all the cable seals, insulators and anode shields were found intact. The use of platinum-clad anodes of the type employed seems economically feasible since the cost of these anodes constitutes a small part of the cost of installation. Laboratory tests indicate the desirability of replacing the copper anode core by a silver core as an insurance against anode failure in the event of a perforation of the platinum cladding. 5.2.3


2004 ◽  
Vol 449-452 ◽  
pp. 125-128
Author(s):  
Jin Seok Oh ◽  
Myung Hyun Lee ◽  
J.D. Kim ◽  
J.Y. Lee

Cathodic protection is a system of preventing corrosion by forcing all surfaces of a hull to be cathode by providing external anodes. A metal can be made cathodic by electrically connecting it to a more anodic metal within the electrolyte. Anodes of these metals corrodepreferentially, the corrosion current of the anode achieving cathodic protection of the underwater hull to which they are connected. This paper presents a new current control algorithm for ICCP (Impressed Current Cathodic Protection) system. The anode of ICCP system is controlled by an external DC source with converter. The function of anode is to conduct the protective current into seawater. The DC source is generally obtained from main power system that contains a transformer, converter and etc. The proposed algorithm can operate AC-DC converter with current link. This algorithm includes the harmonic suppression control strategy and the optimum protection strategy and has tried to test the requirement current density for protection, the influence of voltage, the protection potential. Also, the properties of ICCP protected hull of ship in seawater are evaluated.


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