RU2488511C2 - Displacement vessel with air cavities - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to ship building, particularly, to displacement vessel with air cavities. Displacement vessel is equipped with the device to creating artificial cavities at flat bottom consisting of transverse nozzle arranged one after another over vessel length and composed of plates, lengthwise limiting keels mounted at bottom and source of forced air feed via pipes under vessel bottom to create and maintain cavities behind said transverse nozzles. Said transverse nozzles can be opened and folded to abut the bottom by their turn about their lengthwise axles arranged at vessel bottom. Said lengthwise keels are composed of elongated inflatable containers.

EFFECT: improved capabilities for navigation in shallow water and rough water.

5 cl, 4 dwg

Description

The invention relates to shipbuilding and for the construction of a displacement vessel with air cavities on the bottom, providing a decrease in hydrodynamic resistance and improving the operational characteristics of the vessel.

A device for creating on the bottom of the ship a single air cavity according to the patent of the USSR No. 1145587. The main element of the device is a bottom recess, inside of which a single air cavity with a wave profile is created. The notch is bounded by a bow redan, side keels and aft inclined plane. To increase the transverse stability of the vessel, longitudinal keels are installed inside the recess, which divide the cavity into sections, and transverse nozzles are installed, which make it possible to create a single cavity during the movement of the vessel. However, the presence of a recess in the bottom leads to a loss of internal volumes. As a result, there is a need to increase the height of the freeboard or increase the height of the coamings of cargo holds to maintain their cargo capacity, which in turn entails an increase in the mass of the hull and a decrease in the carrying capacity of the vessel. In addition, the device can only be used on ships of a new construction.

Also known is a ship with a device for forming on its bottom a system of successive air cavities and maintaining the latter (USSR Author's Certificate No. 288576 of December 3, 1970, in application No. 899822 of May 11, 1964) - a prototype. The main elements of the device are transverse nozzles made in the form of inclined plates mounted on a flat section of the bottom. The distance between adjacent transverse nozzles is taken equal to the maximum length of the cavity at the estimated speed of the vessel. From the sides, the caverns are limited by longitudinally bounding keels installed on the bottom. The height and length of the longitudinal keels is taken so that the air supplied under the bottom to create and maintain caverns cannot be vented through them into the atmosphere. Air from the air source through the pipe system is supplied either to each transverse nozzle, or only to some of them, but always to the first (nasal) transverse nozzle. The device can be used both on newly built and on existing ships.

The main disadvantage of the known device is the fact that the limiting and intermediate longitudinal keels significantly protrude beyond the main plane of the bottom (for river vessels - by 0.3-0.4 m), which in conditions of a limited channel depth in shallow water leads to the need to reduce the estimated draft of the vessel and, accordingly, to the inevitable loss of its carrying capacity (by 10-20%, depending on the estimated draft). In addition, the device elements protruding beyond the main plane of the bottom could be easily damaged if the ship was stranded, when faced with an underwater obstacle, or if the fairway depth was significantly reduced.

In addition, these devices are characterized by a sharp decrease in their efficiency when moving in conditions of severe excitement or when moving with a significant initial trim of the vessel. In these cases, the hydrodynamic resistance of a vessel with air cavities, especially when using transverse nozzles protruding beyond the main plane of the bottom in the form of inclined plates, can even be higher than that of a traditional vessel.

The objective of the invention is to improve the operational characteristics of a displacement vessel with air caverns on the bottom in conditions of limited fairway, in shallow water, when moving with a significant initial trim of the vessel and in conditions of movement on intense waves by maintaining the estimated draft of the vessel and, accordingly, reducing its resistance by excitement and movement with a significant initial trim.

This is achieved by the fact that in a displacement vessel with air cavities on the bottom, equipped with a device for creating artificial cavities on the flat bottom, consisting of transverse nozzles following one after another along the length of the vessel on the bottom in the form of inclined plates and longitudinally bounding keels installed on the bottom side, as well as a source of forced air supply through the pipelines under the bottom of the vessel to create and maintain caverns formed behind the transverse nozzles, according to the invention, the said transverse nozzles filled with the possibility of their opening and folding with fit to the bottom by turning them around their longitudinal axes located on the bottom of the vessel, and the longitudinal keels are made in the form of inflated containers of elongated shape.

In addition, intermediate longitudinal keels are installed on the bottom between the outboard longitudinally bounding keels.

Along with this, the limiting and intermediate longitudinal keels are made split - in the form of separate, successive parts, while the gaps between adjacent sections of the longitudinal keels are made with the possibility of minimizing the amount of air bleeding into the atmosphere supplied under the bottom of the vessel.

In the particular case of the proposed solution, the displacement vessel is equipped with a pneumatic drive designed to open and fold the transverse nozzles, inflate the limiting and intermediate longitudinal keels, as well as a system for monitoring and maintaining the running roll and trim within specified limits.

The execution of transverse nozzles with the possibility of their removal by opening and folding with fit to the bottom by turning them around their longitudinal axes located on the bottom of the vessel, along with inflatable longitudinal keels, ensures, in conditions of limited fairway and in shallow water, the settlement draft of the vessel and its drag reduction in conditions of movement with strong waves or with a significant initial trim, when the need to use transverse nozzles protruding beyond the main plane of the bottom and granichitelnyh keels disappears. In addition, this eliminates the possibility of damage to the nozzles protruding beyond the main plane and the limiting keels during the passage of the vessel in shallow shallow areas, locking, the possibility of landing the vessel aground, reversing, etc.

The essence of the invention is illustrated by drawings, in which Fig. 1 schematically shows a displacement vessel with air cavities on the bottom (side view), Fig. 2 is a section A-A in Fig. 1, and Fig. 3 is a diagram of folding the transverse nozzle.

On the bottom 1 of the vessel 2 there are transverse nozzles 3 in the form of inclined plates, which form air cavities 4 and support them, and longitudinal keels 5 are installed on the bottom 1, limiting laterally formed cavities 4 and preventing air from the caverns 4 to be carried away from the side of the vessel 2 (figures 1 and 2). To increase the lateral stability of the vessel and prevent air from flowing from side to side, the caverns 4 are separated by intermediate longitudinal keels 6 into several longitudinal sections 7 isolated from each other (Fig. 2). The height and length of the longitudinal keels 5 is taken such that the air supplied under the bottom to create and maintain caverns cannot be vented through them into the atmosphere. The transverse nozzles 3 can be folded on the bottom 1 by turning them around their longitudinal axes 8 located on the bottom of the vessel (figure 3). Inflatable limiting 5 and intermediate 6 longitudinal keels also have the ability to fold on the bottom by bleeding air from them. (figure 2). Air from the keels is vented to the atmosphere by hydrostatic pressure. When folded, the transverse nozzles 3, restrictive 5 and intermediate 6 longitudinal keels, folding on the bottom, are pressed to it, practically not protruding beyond the main plane of the vessel's vessel (Figs. 1 and 2).

The vessel is equipped with a source of forced air supply 9 (blower or compressor) through pipelines 10 (Fig. 1) to create and maintain cavities formed behind the transverse nozzles 3. Moreover, air can be supplied to each transverse nozzle 3 or only to several nozzles, but the first (nasal). In the latter case, the formation of the remaining caverns is ensured by air carried away from the caudal caudal located nasally. This air supply option simplifies the design and reduces energy losses due to the resistance of the pipelines 10.

To ensure the folding and opening of the limiting 5 and intermediate 6 longitudinal keels, they are made split - in the form of separate, successive parts. In this case, the gaps between adjacent sections of the longitudinal keels 5 are made with the possibility of minimizing the amount of bleeding into the atmosphere of air supplied under the bottom of the vessel.

The vessel 2 is equipped with a pneumatic drive (not shown in the figures) designed to open into the working position and fold the transverse nozzles 3, as well as to inflate the limiting 5 and longitudinal 6 keels.

To increase the efficiency of using air cavities, the vessel is equipped with a system for monitoring and maintaining the running roll and trim within specified limits (not shown in the figures).

The operation of the device is as follows.

If it is necessary to create air cavities on the vessel’s bottom, the transverse nozzles 3 are opened to the calculated angles by means of a pneumatic drive by turning them around their longitudinal axes 8. The longitudinal limiting 5 and intermediate 6 keels are inflated with air. Using a source of forced air supply 9, air is supplied to the area of the transverse nozzles 3, moreover, air is necessarily supplied to the first nasal nozzle, and the formation of the rest following the first nozzle is ensured by air carried out from the caudal tail located nasally. The resulting caverns 4 provide a reduction in the friction resistance of the vessel during its movement.

In the case of movement of the vessel in conditions of limited depth of the fairway, in shallow water, strong waves or with a significant initial trim of the vessel, to prevent the risk of damage to the transverse nozzles 3 and longitudinal keels 5 and 6 protruding beyond the main plane, as well as to reduce the resistance to movement of the vessel on waves or when moving with a significant initial trim, the nozzles are forcibly folded by turning them around their longitudinal axes 8, and the longitudinal keels 5 and 6 are deflated to fit to the bottom 1.

The aft parts 12 of the transverse nozzles 3 define the place and the angle of descent of the air caverns 4. The caverns 4, except the last (aft), smoothly close on the transverse nozzles 3. The last cavity closes on the flat bottom of the vessel. On the sides of the cavity 4, they are limited to the longitudinally installed longitudinal limiting keels 5, which prevent air from escaping from the caverns towards the side.

Figure 4 shows a variant of the proposed device, in which the height of the intermediate transverse nozzles is less than the height of the bow (first) and stern (last) transverse nozzles. In this case, a single air cavity with a wave profile 13 can be formed on the bottom 1 of the vessel 2. This cavity is formed by the forward transverse nozzle and closes on the aft transverse nozzle. To ensure a smooth flow around the feed transverse nozzle, a short cavity 4 is formed behind it, which closes on a flat bottom.

Depending on operating conditions, the effect of reducing the hydrodynamic resistance of vessels with a cavity on the bottom can be realized in two ways: by saving fuel while performing the same amount of transport work as a traditional vessel, or by increasing the volume of transport work due to an increase in the speed of the vessel with caverns at constant power of the main engines.

The proposed displacement vessel is largely free from shortcomings that are unavoidable in the case of using a previously developed modification - prototype; it has greater operational reliability, does not lead to a noticeable decrease in carrying capacity, and when driving on intense waves or with a significant initial trim - to an increase in the hydrodynamic resistance of the vessel, which compares favorably with the prototype.

Claims (5)

1. A displacement vessel with air cavities on the bottom, equipped with a device for creating air cavities under the bottom, consisting of transverse nozzles next to each other along the bottom of the vessel in the form of inclined plates and longitudinally bounding keels installed on the bottom side, as well as a source of compulsory air supply through the pipelines under the bottom of the vessel to create and maintain caverns formed behind the transverse nozzles, characterized in that the said transverse nozzles are made with the possibility of NOSTA their opening and folding adjacent the bottom by turning them around their longitudinal axes disposed at the bottom of the ship and the longitudinal fins are formed as elongated inflatable containers. 2. The displacement vessel according to claim 1, characterized in that intermediate longitudinal keels are installed on the bottom between the outboard longitudinally bounding keels. 3. The displacement vessel according to claim 2, characterized in that the limiting and intermediate longitudinal keels are made split - in the form of separate, successive parts, while the gaps between adjacent sections of the longitudinal keels are made with the possibility of minimizing the amount of air released into the atmosphere under the bottom of the vessel. 4. A displacement vessel according to any one of claims 1 to 3, characterized in that it is equipped with a pneumatic drive designed to open into the working position and fold the transverse nozzles, as well as to inflate the limiting and intermediate longitudinal keels. 5. A displacement vessel according to any one of claims 1 to 3, characterized in that it is equipped with a system for monitoring and maintaining the running roll and trim within specified limits.

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