| 主权项 |
1. An apparatus providing thrust to an object in a liquid comprising:
(a) least one blade that can move through said liquid with a leading edge and a trailing edge, a base and a tip, and with material in between that form a surface or surfaces on each side of said blade, (b) means for attaching said blade or blades to said object, (c) means for moving said object relative to said liquid, (d) means for providing a gas to at least one side of said blade or blades,
such that said blade or blades can be moved by said object through and separate said liquid with enough speed and angle of attack to generate a high pressure in said liquid on one side of said blade or blades and a low pressure in said liquid on said other side of said blade or blades,whereby said blade or blades can displace or accelerate enough liquid with said high pressure side to create required hydrodynamic thrust on said blade or blades in generally a perpendicular angle to the direction of said movement of said blade or blades, and,furthermore, said low pressure can draw in said gas to form a void in said liquid contiguous to said low pressure side, said void being able to extend behind said trailing edge in said liquid,whereby said liquid has substantially reduced contact with said low pressure side, and said blade can travel through said liquid with substantially reduced parasitic drag from wetted surface area, andwhereby said blade is not subjected to sudden loss of hydrodynamic thrust due to cavitation as speed through said liquid is increased, andwhereby said blade is not subjected to sudden loss of lift due to rapid surface venting as speed through said liquid is increased. |
