Marine propulsion device with gaseous boundry layer for a thrust jet flow stream exhibiting stealth and ice lubrication properties

摘要

An engine or motor is attached in a driving relationship to a water moving device, such as a pump, and a thrust outputing portion, such as a nozzle. Heat generated by and rejected by the engine or motor is passed into the pump base for dissipation into the outputtted jet stream. A supply of gas, such as air, and/or exhausted gases from the motive source is ejected around the outputted water stream in a critically defined boundary layer to reduce (1) against-the-hull turbulence induced by the ejected water flow, (2) water jet stream or thrust energy losses (3) vessel afterbody wake losses, (4) propulsion system underwater noise created by the ejected water stream (acoustical isolation), and (5) the contact friction of water born debree against the vessel hull.