Open sea hydrofoil craft

Abstract

An open sea hydrofoil craft comprising a hull (A) with lateral vertically oriented blades (B 1, B 2 ) extending longitudinally along the two sides thereof, the interior surfaces of blades (B 1, B 2 ) lying one opposite the other being planar and defining in between them an initially convergent and subsequently divergent water flow channel, whilst their exterior surfaces have a curved configuration that dynamically changes in three dimensions (x, y, z) with variable angular parameter (Φ 1 ) formed by the bottom of blades (B 1, B 2 ) with (y) axis, (Φ 2 ) formed by the curved section of the exterior surfaces or blades (B 1, B 2 ) with (z) axis and (Φ 1 ,Φ 2 ) formed by an arcuate lateral edge ( 20 ) of blades (B 1, B 2 ) with (x) axis. Lift producing foils (C 1, C 2, C 3 ) with a hydrofoil section are provided within the channel formed in between blades (B 1, B 2 ), these lift producing foils (C 1, C 2, C 3 ) being connected to the hull (A) by means of supporting plates (C 1 ′, C 2 ′, C 3 ′) respectively.

1 . Open sea hydrofoil craft comprising a hull (A) with or without a superstructure (D), a pair of lateral vertically oriented blades (B 1 , B 2 ) being mounted onto the hull (A) and extending longitudinally along the two sides of the hull (A), wherein the interior surfaces of the blades (B 1 , B 2 ) that lie opposite one another are planar, characterized by that:
 the exterior surfaces of blades (B 1 , B 2 ) have the configuration of a curve that dynamically changes in three dimensions (x, y, z), wherein axis (x) extends longitudinally along the vessel, axis (y) extends laterally along the vessel and axis (z) extends vertically, wherein the fore ends of said interior and exterior surfaces of blades (B 1 , B 2 ) converge to form thin vertically oriented bow edges, thereafter gradually diverging towards the stern of the vessel defining a space ( 21 ) wherein engine rooms and reservoirs are being installed, wherein the dynamically changing curved configuration of said exterior surfaces of blades (B 1 , B 2 ) conforms with the following variable parameters:   an angle (Φ 1 ) formed by the bottom of each one of said blades (B 1 , B 2 ) with the (y) axis, said angle (Φ 1 ) varying from a minimal value of the order of 5° at the stern that gradually increases to 90° close to the bow of the vessel;   an angle (Φ 2 ) formed by the curved section of the exterior surface of each one of said blades (B 1 , B 2 ) with the vertically oriented axis (z), said angle (Φ 2 ) varying from a maximum value of the order of 30° at the stern that is gradually diminished to 0° close to the bow of the vessel;   angles (Φ 3 ) and (Φ 4 ) formed an arcuate longitudinally extending lateral edge ( 20 ) of each one of the blades (B 1 , B 2 ) with the horizontally oriented axis (x) passing from the naval frame of maximum breadth that is located close to the region of the middle of the length of the vessel, wherein the head of the arc of the arcuate lateral edge ( 20 ) passes from the naval frame of maximum breadth and the side of the arc heading towards the bow and defining the angle parameter (Φ 3 ), as well as the side of the arc heading towards the stern and defining the angle parameter (Φ 4 ) have a regularly increasing upward and inward inclination ending at said thinned bow edges on the one side and at gradually relatively thinned stern portions of blades (B 1 , B 2 ), wherein the value of the angular parameters (Φ 3 , Φ 4 ) depends on the overall constructional architecture of the vessel;   wherein said lateral vertically oriented blades (B 1 , B 2 ) are interconnected with an arrangement of lift producing foils (C 1 , C 2 , C 3 ) extending laterally intermediately between said blades (B 1 , B 2 ) all along the distance between opposite planar surfaces thereof, said lift producing foils (C 1 , C 2 , C 3 ) having a hydrofoil section with a leading edge oriented in the direction of the bow and being provided with vertically extending and longitudinally oriented, substantially parallel to said planar surfaces of blades (B 1 , B 2 ), central supporting plates (C 1 ′, C 2 ′, C 3 ′) respectively, said central supporting plates (C 1 ′, C 2 ′, C 3 ′) being fixedly mounted onto said hull (A), each one of said lift producing foils (C 1 , C 2 , C 3 ) having a differentiated configuration and being located at a differentiated distance from the vessel's waterline during cruising and at a differentiated distance relatively to the bottom of said lateral vertically oriented blades (B 1 , B 2 ).   
   
   
       2 . Open sea hydrofoil craft as claimed in above  claim 1 , characterized by said first fore lift producing foil (C 1 ) being located at a certain distance from the bottom edges of said blades (B 1 , B 2 ) and said third aft lift producing foil (C 3 ) being located lower than said fore lift producing foil (C 1 ) the distance thereof from the bottom edges of said blades (B 1 , tending to zero, both said fore lift producing foil (C 1 ) and aft lift producing foil (C 3 ) being oriented perpendicularly onto said interior planar surfaces of blades B 2 ), wherein due to the differentiated distance of said fore lift producing foil (C 1 ) and of said aft lift producing foil (C 3 ) from the bottom edges of said blades (B 1 , B 2 ) a counterclockwise rotational moment arises, said rotational moment increasing as the speed of the vessel increases, said rotational moment eliminating the otherwise occurring undesirable rising of the bow of the vessel and subsequent falling thereof as the vessel cruises at high speed that are associated with periodical hard strokes of the vessel into the water mass and may also lead into a tendency of the vessel being overturned. 
   
   
       3 . Open sea hydrofoil craft, according to the above  claims 1  and  2 , characterized by that each one of said vertically extending central supporting plates (C 1 ′, C 2 ′, C 3 ′) respectively of said lift producing foils (C 1 , C 2 , C 3 ) is perforated with apertures ( 10 ) through which water flows freely on either side of said supporting plates (C 1 ′, C 2 ′, C 3 ′) thereby balancing pressures, if any, that may be due to a sideward inclination of the vessel. 
   
   
       4 . Open sea hydrofoil craft, according to the above  claim 1 , characterized in that said interior planar surfaces of the vertically extending blades (B 1 , B 2 ) longitudinally extending along the sides of the hull (A) do form, in the direction from the bow towards the stern, an initially slightly convergent and subsequently a slightly divergent channel, said intermediate lift producing foil (C 2 ) being located at the end of the slightly convergent channel portion whereby the span of said intermediate lift producing foil (C 2 ) is less than the span of either said fore lift producing foil (C 1 ) or the span of said aft lift producing foil (C 3 ), said intermediate lift producing foil (C 2 ) comprising two identical portions (C 2   a , C 2   b ) symmetrically extending on one and the other side of the vertically extending central supporting plate (C 2 ′) by means of which said intermediate lift producing foil (C 2 ) is connected to the hull (A), said symmetrically oriented identical portions (C 2   a , C 2   b ) forming an obtuse angle so as to render an overall configuration of inverse V of said intermediate lift producing foil (C 2 ), said intermediate lift producing foil (C 2 ) being located at a certain distance from the bottom edges of said blades (B 1 , B 2 ) higher than said fore and aft lift producing foils (C 1 , C 3 ) thereby producing, in addition to the lift effect, a laminar flow with the water masses being directed towards the center of the channel being formed by said vertically extending blades (B 1 , B 2 ) thereby enhancing the kinetic energy thereof. 
   
   
       5 . Open sea hydrofoil craft, according to the above  claim 1 , characterized in that said fore lift producing foil (C 1 ) is provided with a complex bulb structure ( 11 ) extending longitudinally along the bottom of said lift producing foil (C 1 ) underneath said central supporting plate (C 1 ′) thereof, said complex bulb structure ( 11 ) protruding afore the leading edge of said fore lift producing foil (C 1 ) and acting so as to smoothly guide the water mass onto said fore lift producing foil (C 1 ) and avert hydraulic strokes thereupon, a pair of side fins ( 11   a ,  11   b ) being provided on either side of said complex bulb structure ( 11 ) longitudinally along the bottom of said fore lift producing foil (C 1 ), said side fins ( 11   a ,  11   b ) lagging behind said complex bulb structure ( 11 ) along only a portion of the length of foil (C 1 ) and acting so as to damp wave making and to enhance the effect of the centrally oriented protruding complex bulb structure ( 11 ). 
   
   
       6 . Open sea hydrofoil craft, according to the above  claim 1 , characterized by that said aft lift producing foil (C 3 ) comprises an arrangement of three conically shaped fins ( 12 ) protruding afore the leading edge thereof, wherein a first one of the three conically shaped fins ( 12 ) lies longitudinally along said central supporting plate (C 3 ′) and the other two conically shaped fins ( 12 ) lie symmetrically along one and the other side of said aft lift producing foil (C 3 ), rightwards and leftwards relatively to said central supporting plate (C 3 ′), said three conically shaped fins ( 12 ) protruding afore the leading edge of said aft lift producing foil (C 3 ) acting so as to eliminate vortices resulting from the wake of said preceding lift producing foils (C 1 , C 2 ) and smoothen pressures and speeds of the water masses falling onto said aft lift producing foil (C 3 ). 
   
   
       7 . Open sea hydrofoil craft, according to anyone of the above  claims 1 - 6 , characterized in that said hull (A) does not come in contact with the sea surface whilst the craft is cruising and has a substantially planar square cross section thereby providing enhanced cargo loading capacity.