Active apparatus and method for reducing fluid induced stresses by introduction of energetic flow into boundary layer around an element

A method for protecting a member from the effects of a fluid current flowing past said member, the current defining a fluid boundary layer near the member, the method comprising:

• (a) suctioning fluid from said fluid boundary layer thru a plurality of fluid passages of a fluid passage member, wherein said fluid passage member comprises a boundary layer surface of the member, wherein each of said plurality of fluid passages comprises a plurality of ports located alone at least a portion of said boundary layer surface, wherein said fluid is suctioned from said fluid boundary layer by said ports and passes through said fluid passages, and wherein said ports are arranged in a helical fashion on the surface of said fluid passage member.

A method for reducing low frequency oscillations of a moored vessel caused by waves or wind striking the vessel, wherein the vessel has a first side and a second side and a plurality of fluid passages extending from the first side to the second side, wherein each of said plurality of passages comprises a first opening positioned on the first side and a second opening positioned on the second side, wherein said first openings are arranged in a helical pattern and wherein said second openings are arranged in a helical pattern and wherein the oscillations of the vessel define an oscillating current of water flowing past the vessel the method comprising:

• (a) pumping water in from either opening when the vessel moves toward said current and out of either opening when the vessel moves away from said current.

A system for reducing the effects of a fluid current flowing past a bluff hull wherein said current defines a fluid boundary layer near the hull, the system comprising:

• (a) a hull defining a fluid passage member having a boundary layer surface, wherein said fluid passage member comprises a plurality of fluid passages, wherein each of said plurality of fluid passages comprises a plurality of ports located along at least a portion of said boundary layer surface, wherein said fluid passes through said ports and into said fluid boundary layer, or out of said fluid boundary layer and through said ports, and wherein said ports are arranged in a helical fashion on the surface of said fluid passage member;
• and
• (b) a pump in communication with the plurality of fluid passages, wherein the pump functions to pass fluid through said fluid passages.