RU2527244C1 - Aft end of two-shaft vessel - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: hull aft end of two-shaft cargo vessel navigating at Froude number values less than 0.15, having block coefficient no less than 0.90 contains transverse ribs formed by board overhangs and keel which smoothly mate in the area of screw buttock passing through line of shafting. Upper branch of screw buttock does not cross construction waterline on "side" projection and has horizontal section at the height of about 97% of vessel draft up to construction waterline.

EFFECT: higher propulsive performance of cargo vessel.

3 cl, 2 dwg

Description

The invention relates to shipbuilding, in particular to the design of the contours of the aft end of the hull.

Known aft end of the vessel with tunnels for locating propulsion systems (patent SU 1627444, B63B 1/08, publ. 02.15.91), containing aft and side overhangs, as well as flat arches of tunnels for accommodating propellers, providing increased propulsive qualities and vibration reduction.

The disadvantage of a vessel with a known aft end is the presence of a stern overhang, which impairs propulsive qualities in free travel, but increases traction characteristics in modes close to the mooring. Without a feed overhang, in the presence of side overhangs, the mover will suck in air, since the size of the mover is usually equal to or greater than the draft. Such contours are characteristic of river tugs and pusher tugs with propellers in rotary or fixed nozzles.

An example is pusher tugboats:

- project No. 947 with a capacity of 4000 hp (with an average draft of 3.0 m, the diameter of the propeller in the rotary nozzle is 2.90 m) (see "Directory of serial transport vessels", volume 3. - M .: Transport, 1974, p.4);

- project No. 4151 with a capacity of 2000 hp (with an average draft of 1.60 m, the diameter of the propeller in the fixed nozzle is 1.63 m) (see J. Shipbuilding, 1965, No. 8).

Such vessels have an increased energy consumption on the fly.

The purpose of the invention is to increase the propulsive characteristics of a two-shaft cargo ship floating at a Froude number at idle of less than 0.15, having a coefficient of total completeness of at least 0, 90, by refusing the aft overhang of the tunnel and placing a propulsion device with a large hydraulic section in the tunnel.

This result is achieved by the fact that the side overhangs of the tunnel in the plane of the frames smoothly mate with the keel, forming a screw buttox in the plane of the gross line, the lower branch of which smoothly flows into the main plane (OP) of the vessel, and the upper branch does not cross the structural waterline on the side projection and has a horizontal section located at an altitude of about 97% of the draft of the vessel along the structural waterline.

Figure 1 presents the projection "side" of the theoretical drawing of the contours of the aft end; figure 2 - projection "body" of this theoretical drawing.

The half-tunnel feed of a two-shaft cargo ship contains side overhangs 5 and keel 6, which smoothly mate in the area of the screw buttock 1, the upper branch of which has a horizontal section 4, located at an altitude of about 97% of the draft.

The screw buttocks 1 passing through the line of the shaft 2, at the intersection with the shaft, have an inflection point, and tangent 3 drawn to the inflection point in the plane of the buttock is inclined to the vessel's OP at an angle α = 13 ° ... 18 °. The angle of inclination of the onboard overhangs β in the plane of the frames is determined between tangent 8 at the inflection point of the onboard overhang and the vessel's OP and varies between 0 ° ... 18 °. The keel 6 serves to increase the displacement and shifts the center of the vessel’s size in the stern, and, together with the side overhangs, forms a half-tunnel in which the propulsion unit 7 is located. The pitch angle γ in the frame plane is determined between the tangent 9 at the inflection point of the keel and the diametrical plane (DP ) vessel and varies within 60 ° ... 90 °.

The proposed contours of the feed end provide gentle buttocks that reduce the shape resistance and create water flow to the propulsors. Behind the movers, the water gradually descends from a wide transom without a strong vortex formation due to the absence of a submerged feed overhang and the presence of a horizontal section of a half-tunnel.

Claims (3)

1. The aft end of the hull of a two-shaft cargo ship floating at a Froude number of less than 0.15, having a coefficient of total completeness of at least 0.90, containing frames formed by side overhangs and a keel that smoothly mate in the area of the screw buttock passing through the shaft line , characterized in that the upper branch of the screw buttock does not cross the structural waterline on the side projection and has a horizontal section located at an altitude of about 97% of the draft of the vessel along the constructive waterline. 2. The feed end according to claim 1, characterized in that the side overhangs in the plane of the frames have an inflection point, the tangent to which and the OP form an angle within 0 ° ... 18 °. 3. The feed tip according to claim 1, characterized in that the diametrical keel in the plane of the frames has an inflection point, the tangent to which and the DP form an angle within 60 ° ... 90 °.

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