Abstract: A marine surface vessel having a main hull and at least two lateral hulls disposed respectively on opposite sides of the main hull. The vessel includes an engine disposed in the main hull producing exhaust gas and cooling air, microbubble injectors disposed in subsurface areas of each of the lateral hulls, and conduits in fluid communication with the microbubble injectors. Upon operation of the engine, the exhaust and/or cooling air produced by the engine is directed by the conduits to the injectors to effect generation of microbubbles on the subsurface areas of the lateral hulls to occasion microbubble drag reduction on the lateral hulls.

Abstract: A method for reducing the drag on an aqueous solution in a pipe or hose system such as a snow making system includes the introduction of drag reducing polymers into the aqueous solution prior to circulating the solution in a pipe or hose. In a preferred embodiment, the drag reducing polymers are a mixture of polyethylene oxide in a carrier solution. The introduction of the polyethylene oxide in a carrier solution reduces the overall frictional drag and therefore increases the snow making efficiency by reducing the power needed to pump the water. As a result, it is easier for greater quantities of snow to be made using existing equipment due to the increased flow rate as a result of the lower drag friction. In a preferred embodiment, the polyethylene oxide is approximately 20-30% by weight and is introduced into the water pipe so resulting concentrations are approximately 30-100 weight parts per million (WPPM).

Abstract: A method for reducing the drag on an aqueous solution in a pipe or hose system such as a snow making system includes the introduction of drag reducing polymers into the aqueous solution prior to circulating the solution in a pipe or hose. In a preferred embodiment, the drag reducing polymers are a mixture of polyethylene oxide in a carrier solution. The introduction of the polyethylene oxide in a carrier solution reduces the overall frictional drag and therefore increases the snow making efficiency by reducing the power needed to pump the water. As a result, it is easier for greater quantities of snow to be made using existing equipment due to the increased flow rate as a result of the lower drag friction. In a preferred embodiment, the polyethylene oxide is approximately 20-30% by weight and is introduced into the water pipe so resulting concentrations are approximately 30-100 weight parts per million (WPPM).

Abstract: Gas bubbles in a moving fluid are collected in a chamber alongside the conduit carrying the fluid. In a preferred embodiment, an ultrasonic transducer cooperates with a reflector to create a standing ultrasonic wave pattern that is oriented at an acute angle to the horizontal axis of fluid flow. Bubbles gather at the troughs between the waves and then move between the pressure waves in the downstream direction to be collected in the chamber. Bouyant forces aid the movement of the bubbles in an upward direction. A gas permeable window at the top of the chamber allows removal of the collected bubbles.

Abstract: The present invention relates to an underwater weapon having a system for aling the opening of a gun barrel to prevent the ingress of water. The sealing system includes a non-metallic or metallic tape for covering and sealing the opening and a mating surface on the gun barrel against which the tape is seated to prevent the ingress of water. The sealing system further includes sprockets for advancing the tape across the opening of the gun barrel and for maintaining the tape in a taut position during operation.