Method for Applying a Coating to an External Surface of a Man-Made Object to Be at Least Partly Immersed in Water

Abstract

The disclosure relates to a method of applying a coating to an external surface of a man-made object to be at least partly immersed in water (e.g. a vessel or an offshore drilling station) for a time period wherein there is relative movement between the immersed object and the water. The applied coating has a minimal resistance rating for a set of coatings. The method comprises a computer-implemented coating selection process, which comprises a first steps of obtaining, for each coating in the set of coatings, a total roughness value of the external surface based on a fouling roughness value, a macro roughness value and a micro roughness value associated with each coating. The coating selection process comprises in a second step selecting a coating from the set of coatings, wherein the selected coating has a minimal resistance rating associated with the obtained total roughness value for the time period. The method further comprises applying the selected coating to the external surface of the man-made object.

1 - 13 . (canceled) 
     
     
         14 . A computer program or suite of computer programs comprising at least one software code portion or a computer program product storing at least one software code portion, the software code portion, when run on a computer system, being configured for executing a coating selection process comprising the steps of:
 obtaining, for each coating in the set of coatings, a total roughness value of the external surface based on a fouling roughness value, a macro roughness value and a micro-roughness value associated with each coating, and   selecting a coating from the set of coatings, wherein the selected coating has a minimal resistance rating associated with the obtained total roughness value for the time period.   
     
     
         15 . A non-transitory computer-readable storage medium storing at least one software code portion, the software code portion, when executed or processed by a computer, configured to perform executable operations comprising the steps of a coating selection process comprising
 obtaining, for each coating in the set of coatings, a total roughness value of the external surface based on a fouling roughness value, a macro roughness value and a micro-roughness value associated with each coating,   selecting a coating from the set of coatings, wherein the selected coating has a minimal resistance rating associated with the obtained total roughness value for the time period.   
     
     
         16 . A method for selecting from a set of coatings a coating having a minimal resistance rating, wherein the coating is to be applied to an external surface of a manmade object to be at least partly immersed in water for a time period wherein there is relative movement between the immersed object and the water, the method comprising the steps of:
 obtaining, for each coating in the set of coatings, a total roughness value of the external surface based on a fouling roughness value, a macro roughness value and a micro-roughness value associated with each coating,   selecting a coating from the set of coatings, wherein the selected coating has a minimal resistance rating associated with the obtained total roughness value for the time period.   
     
     
         17 . The computer program according to  claim 14 , wherein the external surface of the man-made object to be at least partly immersed in water comprises a hull of a vessel. 
     
     
         18 . The computer program according to  claim 17 , wherein the external surface is segmented in a Boot Top part, a Vertical Side part and a flat Bottom part. 
     
     
         19 . The computer program according to  claim 18 , wherein the minimal resistance rating is calculated by a Computational Fluid Dynamics model based on at least one of the total roughness value, a shape and size of the man-made object, and an operational speed of the man-made object 
     
     
         20 . The non-transitory computer-readable storage medium according to  claim 15 , wherein the external surface of the man-made object to be at least partly immersed in water comprises a hull of a vessel. 
     
     
         21 . The non-transitory computer-readable storage medium according to  claim 20 , wherein the minimal resistance rating is calculated by a Computational Fluid Dynamics model based on at least one of the total roughness value, a shape and size of the man-made object, and an operational speed of the man-made object 
     
     
         22 . The computer program according to  claim 18 , wherein a calculation of the fouling roughness value associated with each coating comprises:
 accessing a roughness database that associates combinations of each coating and a geographical region where the man-made object is expected to be located during the time period with a respective static fouling roughness value;   retrieving the static fouling roughness value;   converting the static fouling roughness value to a dynamic fouling roughness value by accounting for an expected activity of the man-made object during the time period;   calculating the fouling roughness value based on the dynamic fouling roughness value and based on an expected change in the fouling roughness value with time.   
     
     
         23 . The method according to  claim 16 , wherein the external surface of the manmade object to be at least partly immersed in water comprises a hull of a vessel. 
     
     
         24 . The method according to  claim 23 , wherein the external surface is segmented in a Boot Top part, a Vertical Side part and a flat Bottom part. 
     
     
         25 . The method according to  claim 24 , wherein the minimal resistance rating is calculated by a Computational Fluid Dynamics model based on at least one of the total roughness value, a shape and size of the man-made object, and an operational speed of the man-made object 
     
     
         26 . The non-transitory computer-readable storage medium according to  claim 20 , wherein a calculation of the fouling roughness value associated with each coating comprises:
 accessing a roughness database that associates combinations of each coating and a geographical region where the man-made object is expected to be located during the time period with a respective static fouling roughness value;   retrieving the static fouling roughness value;   converting the static fouling roughness value to a dynamic fouling roughness value by accounting for an expected activity of the man-made object during the time period;   calculating the fouling roughness value based on the dynamic fouling roughness value and based on an expected change in the fouling roughness value with time.   
     
     
         27 . The method according to  claim 24 , wherein a calculation of the fouling roughness value associated with each coating comprises:
 accessing a roughness database that associates combinations of each coating and a geographical region where the man-made object is expected to be located during the time period with a respective static fouling roughness value;   retrieving the static fouling roughness value;   converting the static fouling roughness value to a dynamic fouling roughness value by accounting for an expected activity of the man-made object during the time period;   calculating the fouling roughness value based on the dynamic fouling roughness value and based on an expected change in the fouling roughness value with time.   
     
     
         28 . The computer program according to  claim 14 , wherein at least one static fouling roughness value associated with a combination of a coating in the set of coatings and the geographical region has been derived by:
 retrieving from a fouling database parameters relating to fouling of a plurality of man-made objects to be at least partly immersed in water that have been in the geographical region and to which the coating was applied;   calculating a fouling score based on the parameters for each man-made object in the plurality of man-made objects, yielding fouling scores;   calculating a representative value of the fouling scores;   obtaining the static fouling roughness value from a table associating the calculated representative value of the fouling scores with the static fouling roughness value.   
     
     
         29 . The computer program according to  claim 28 , wherein the plurality of manmade objects is divided into at least two subgroups, wherein each of the at least two subgroups is associated with a respective range of fouling scores, wherein the respective ranges do not overlap and wherein each subgroup comprises only man-made objects that have fouling scores within the respective range of each subgroup; and
 wherein for each subgroup a separate average is calculated, and subsequently a separate static fouling roughness value, a separate dynamic fouling roughness value, a separate fouling roughness value and a separate total roughness value.   
     
     
         30 . The computer program according to  claim 14 , wherein the macro roughness value is derived by:
 calculating a macro roughness score based on at least one of an initial substrate macro roughness score , a coating macro roughness score-, and a time-dependent macro roughness score;   calculating the macro roughness value based on the macro roughness score.   
     
     
         31 . The computer program according to  claim 30 , wherein the micro roughness value is derived by:
 calculating a micro roughness score based on an initial micro roughness score and a time-dependent micro roughness score;   calculating the micro roughness value based on the micro roughness score.