Polymer drag reduction systems on vehicle surfaces

A reduced drag vehicle, comprising:

• a structure having a forward end, an interior, and an outer surface;
• a plurality of water inlets in the forward end through which water can flow into the interior of the structure;
• a mixing chamber in the interior of the structure in fluid communication with the plurality of water inlets and receiving water that flows into the structure through the plurality of water inlets;
• a polymer within the interior of the structure in communication with the mixing chamber, the polymer mixes with the water in the mixing chamber to form a polymer solution;
• a plurality of polymer solution outlets in the outer surface in fluid communication with the mixing chamber through which the polymer solution is ejected from the structure into a boundary layer to reduce drag on the outer surface as the structure moves in a forward direction through water with the water flowing past the forward end and then over the polymer solution outlets in the outer surface;
• the plurality of water inlets are positioned forwardly of the plurality of polymer solution outlets;
• the plurality of polymer solution outlets are positioned rearwardly of at least a portion of the mixing chamber;
• the pressure at the water inlets is higher than the pressure at the polymer solution outlets so that the polymer solution is passively ejected from at least one of the polymer solution outlets;
• the polymer is a liquid polymer that is contained in a storage chamber that is fluidly connected to the mixing chamber;
• and
• wherein the storage chamber is a compressible bladder, the compressible bladder is exposed to ambient pressure of water that the reduced drag vehicle is operating in, and further comprising a force applying mechanism acting on the compressible bladder.

A reduced drag vehicle, comprising:

• a structure having an interior, a forward end, and at least one outer surface that is subject to drag as a result of the structure moving in a forward direction through water with the water flowing past the forward end and then over the at least one outer surface;
• a compressible bladder contained in the interior of the structure and exposed to ambient pressure, the compressible bladder containing a liquid polymer;
• a mixing chamber in the interior of the structure in fluid communication with the compressible bladder to receive liquid polymer therefrom;
• a metering valve that controls the flow of liquid polymer from the compressible bladder into the mixing chamber;
• at least one water inlet on the structure through which water can flow into the interior of the structure, the at least one water inlet is fluidly connected to the mixing chamber;
• wherein liquid polymer from the compressible bladder and water from the at least one water inlet mix in the mixing chamber to form a polymer solution;
• a polymer solution discharge line fluidly connected to the mixing chamber;
• at least one polymer solution outlet formed in the at least one outer surface that is subject to drag and fluidly connected to the polymer solution discharge line to discharge polymer solution from the at least one polymer solution outlet to reduce drag on the at least one outer surface;
• and
• the pressure at the at least one water inlet is higher than the pressure at the at least one polymer solution outlet so that the polymer solution is passively ejected from the at least one polymer solution outlet without use of an electrically driven pump.

A reduced drag vehicle, comprising:

• a structure having an interior, a forward end, and at least one outer surface that is subject to drag as a result of the structure moving through water with the water flowing past the forward end and then over the at least one outer surface;
• at least one water inlet on the structure through which water can flow into the interior of the structure;
• a mixing chamber in the interior of the structure and fluidly connected to the at least one water inlet and receiving water that flows into the structure through the at least one water inlet;
• a water-soluble solid polymer disposed in the mixing chamber, wherein water entering the mixing chamber dissolves at least a portion of the water-soluble solid polymer to form a polymer solution in the mixing chamber;
• at least one polymer solution outlet formed in the at least one outer surface that is subject to drag and fluidly connected to the mixing chamber to discharge polymer solution from the at least one polymer solution outlet to reduce drag on the at least one outer surface;
• the at least one water inlet is positioned forwardly of the at least one polymer solution outlet;
• and
• the at least one polymer solution outlet is positioned radially outward of the water-soluble solid polymer and the mixing chamber.

A reduced drag vehicle, comprising:

• a structure having an interior, a forward end, and at least one outer surface that is subject to drag as a result of the structure moving through water with the water flowing past the forward end and then over the at least one outer surface;
• at least one water inlet on the structure through which water can flow into the interior of the structure;
• a mixing chamber in the interior of the structure and fluidly connected to the at least one water inlet and receiving water that flows into the structure through the at least one water inlet;
• a water-soluble solid polymer disposed in the mixing chamber, wherein water entering the mixing chamber dissolves at least a portion of the water-soluble solid polymer to form a polymer solution in the mixing chamber;
• at least one polymer solution outlet formed in the at least one outer surface that is subject to drag and fluidly connected to the mixing chamber to discharge polymer solution from the at least one polymer solution outlet to reduce drag on the at least one outer surface;
• the at least one water inlet is positioned forwardly of the at least one polymer solution outlet;
• the at least one polymer solution outlet is positioned radially outward of the water-soluble solid polymer and the mixing chamber;
• and
• wherein the structure is a duct of a propulsion mechanism, and the at least one outer surface is an outer surface of the duct.