DISPLACEMENT0TYPE VESSEL WITH AIR LAYER UNDER BOTTOM Russian patent published in 2001 - IPC

FIELD: shipbuilding; designing vessel with reduced wetted surfaces of bottom. SUBSTANCE: cavity formed in bottom is communicated with compressed air source and is bounded by side skegs provided with water-separating edges. Aft closing of bottom arch is found between skegs. At least one transversal planning step is mounted in cavity. Lower edge of planning step does not extend beyond boundaries of above-mentioned edges. Point of intersection of these edges lies in ship's CL, in fore section. Water-separating edge of each skeg lies in line of each n_i approximated elementary sections where 1<n_i≅10⁶. Sections form angle α_i with ship's CL which is taken within 0^°≅ α_i≅ 90^°. Length L₁ of water-separating edge over each side skeg from point of their intersection in fore portion relative to maximum length L₂ is selected within 0,2≅L₁/L₂<1,0. Approximated elementary sections of water-separating edges are formed by planes located in zones of contact with water and air cavity form angle i at each β_i-elementary section which is selected within 30^°≅ β_i≅ 170^°. Intersection of water-separating edges does not extend beyond area where line of keel changes into stem. Angle α_i of water-separating edge of each skeg with ship's CL may gradually decrease from point of intersection of edges in fore portion towards aft portion. Skegs may be made in form of projections or inclined plates. EFFECT: possibility of forming cavity optimal shapes for maintaining similar layer in wide ranges of running speeds. 4 cl, 6 dwg, 1 tbl