WAVE MAKING ENERGY ABSORBER DURING VESSEL'S PROPULSION

Abstract: The invention refers to the Hydrodynamic technical field. It concerns the installation of a wave making energy absorber or external conductor placed forward of the bow and extending aft of the same, if necessary. This conductor extends below or below and above the water level, taking into consideration full load and ballast condition of a vessel. The abovementioned wave making energy absorber, i.e. the external conductor mounted forward of the bow, with or without aft of bow extending legs, has to be symmetrically constructed. It is possible too, this external forward of bow conductor or in other words wave making energy absorber on a vessel, to create a conductor with or without legs of constant or divergent or convergent section or any combination of the abovementioned sections.

Description: DESCR I P T I . ON aye_ akin2_ene r2ϊ___bso rbe _du rin2_y The invention refers to the hydrodynamic field and i concerns, the instal lation of an external conductor cal l absorber, placed forward of the bow of a vessel, extendi aft of the bow too, either as a single conductor or divide in two parts if necessary. THE_PR1QR_ART The state of the art faces the propulsion problem of vessel, in order to decrease partial ly the wave makin energy losses, by instal l ing a bolbous bow at forward end, o a conductor or conductors' system inside the vessel whic starts from the bow and ends at the sides or at the aft en of a vessel . However this entai ls a significant increase o friction losses due to the large length of the conductor, an the decreasing displacement, due to the conductor's volume in the case where the conductors run along the entire lengt of the vessel . Consequently the prorulsion power per cubi meter of displacement or transported volume (HP/cubic meter is increased, that is we are going to have less transporte capacity for the same power, which is equivalent to increase fuel oil and lubricants consumption for the same transporte cargo capacity. However, the bolbous bow also decreases the wave makin resistance but the decrease attained thereby is comparativel less than the decreas-e attained by the proposed wave makin energy absorber arrangement. Consequently the state of the art practically is not s economical in comparison to the proposed invention. Into thi invention, vessel 's displacement is kept unchanged having better hull efficiency, due to the decrease of propulsio resistance by instal l ing a wave making energy absorber. Th obtained efficiency being much larger than the efficienc obtained in the prior art, in the abovementioned manner, th present invention provides a substantial decrease of the wave making resistance. BEIIF_DESCRIPTI0N_0F_THE_DRAWIN6S The invention will be made clearly apparent to those skilled in the art by reference to the accompanying drawings, wherein are depicted illustrative views of the invention. Figure 1 shows in accordance to a first embodiment of the invention a side view of the vessel at the bow of which is installed the proposed conductor-wave ma ing energy absorber. Figure 2 shows a plan view or section A-A of figure 1. Figure 3 shows a front view or section B-B of figure 1. Figure 4 shows in accordance to an alternativ embodiment of the invention a side view of the vessel, a the bow of which is instal led the proposed conductor - wav making energy absorber divided at the bow to a pair of leg extending on either side of the vessel . Figure 5 shows a plan view or section C-C of figure 4. Figure 6 shows a front view or section D-D of figure 4. The various points i l lustrated in the accompanyin drawings are enl isted below in an order corresponding t their reference numerals in the accompanying drawings. 1. Vessel or hu 11. 2. External conductor-wave making energy absorber place forward of the bow 3. Supporting and reinforcing elements. 4. Legs of conductor 2 extending on either side of th bow . DII I ID_DESCRIPTIQN_OF_THE_INVENTION Referring now to the attached drawings, the inventio wi l l be described in an i l lustrative manner. According to th first embodiment of the invention an external conductor i mounted forward of the bow on a vessel, extending below o below and above the water l ine of the vessel . This conducto - wave ma ing energy absorber has a certain length in orde to accomplish the aim of the invention, that is to extingnis or reduce the wave making energy losses. When the sea wate enters through at least one or more inlet openings and i discharged through at least one or more outlet openings th vessel 's wave making is reduced. The manner in which the invention is implemented i presented in Figures 1—3, wherein are shown a side view, section A-A and a section B-B. The side view also shows th height of this external conductor - wave ma ing energ absorber 2, and the distance of the conductor from th external si e of a vessel 1. This conductor-wave making energy absorber extends i accordance to an alternative embodiment of the invention af of the bow,being divided in at least two legs with one outle opening on each of those legs. In accordance to a further alternative embodiment of th invention, it is possible to ommit the conductor extendin forward of the legs, so that sea water enters directly int at least one of the legs extending on either side of th vessel and is discharged through at least one outlet opening. Therefore, the energy lost, due to the wave making durin the propulsion of the vessel τi sea water, is absorbed and thereby reduced. Consequent ly, 1 ess power is required for the same displacement of the vessel, and transportation of a cargo volume unit is thereby made cheaper. Conductor supporting elements 3, support this external conductor 2 on the hull 1, the conductor itself and/or legs 4 extending on either side have hydrodynamic shape to obtain the best possible efficiency of this arrangement. In this way, we are going to have a wave making decreas which being absorbed as abovementioned results in a mor economic transportation, because due to the wave makin decrease we shal l have a decrease of the total resistanc during vessel 's propulsion, which is equivalent to th propulsion power corresponding decrease and final ly a fue oi l and lubricants decrease for the same displacement an speed . The size and hydrodynamic shape (i f required) of th conductor as w l l as the hydrodynamic shape of the supportin elements, the distance from the center l ine of this externa conductor-wave making absorber depends on vessel 's size design or cruise speed and displacement. It must hereby be noted that either the single conducto 2 or the conductor 2 divided into two legs 4 or even simpl the two legs 4, right from the inlet opening to the outle opening or openings, may have any desired l inear or curve shape and may either be of a c i rcumferent i a 11 y compac structure or it may include partial openings, e.g. in it vertical ly defined upper and/or lower sides. Openings and/o slots and/or grooves of a desired number, form an arrangement, by means of which a balancing of pressures i obtained, may also be provided at the flow region between th inlet opening or openings up to the outlet opening o openings. It must also be noted that, in accordance to a i l lustrative embodiment of the invention, a portion of eithe wave ma i g energy absorber 2 mounted forward of the bow and/or the abovementioned bow's aft extending legs 4 may be incorporated into the hull, thereby suitably modifying bow's geometry, hi 1 st it is also possible that the conductor or legs are mounted on th& hull in combination to the existing technology of bow's bulb. All the abovementioned facts are naturally valid both with vertical bow vessels as well as vessels ith a bow inclined at any desired inclination. It is understandable too that, the proposed arrangement, concerning the advantageous mounting of the wave making energy absorber, is equal lly valid with vessel the vessel being either fully or partially loaded and independentl of the ballast condition. The invention can be implemented at any desirable form design or si ze . The figures (drawings), being attached to the present description . do not constitute a confining form of the invention, but simply an illustrative one. Any other modification that does, not constitute a new inventive step and does not contain elements of a new invention does not restrict the rights claimed in the present invention. The construction of the invention is being realised by profile iron and steel plates or other desired properly shaped materials. Their dimensions depend proportionally on the ship's dimensions and design or cruise speed, being desired. By the term "conductor" is meant not only the one of a circular section but that of any section transversa 11 y and longitudinal ly, the section being either constant or convergent or divergent section or a combination of two or more sections. The proposed inventions effects an absorbing of the energy losses due to wave-making. By the term "supports" are meant steel constructed or other material pieces, which are being used as supports of the said bow's -external or partialy incorporated in the hul l - conductor, these supports being hydrodyna i ca 11 y shaped or not .

Claims: CLA IMS 1. Wave making energy absorber during vessel ' propulsion, mounted forward of the bow and comprising a external conductor, which includes at least one inlet openin and at least one outlet opening, a passage being defined for the flow of sea water in between said inlet and said outlet opening, said conductor extending below or below and above the water l ine level, where the sea water entering through said at least one inlet opening and exiting through said at least one outlet opening effects a reduction of the wave making losses. 2. Wave making energy absorber during vessel 's propulsion, in accordance to above claim 1, said conductor extending aft of the bow line, being divided to at least two legs, each side leg having at least one inlet and at least one outlet opening for the sea water flow. 3. Wave making energy absorber during vessel 's propulsion, in accordance to any of the above claims 1,2, wherein said conductor and/or said aft of the bow line at least two legs have a constant or divergent or convergent section or the combination of two or more sections in parts. 4. Wave making energy absorber during vessel's propulsion, in accordance to any of the above claims 2-3, comprising immediately aft of the bow line at least two longitudinally extending said legs, where each of said legs includes at least one outlet opening of the sea water flow, said see water flow being directly introduced into said at least two legs, extending on either side of the bow. 5. Wave making energy absorber during vessel propulsion, in accordance to any of the above claims 1- where the entire length or a portion of length of sa conductor extending from said at least one inlet opening to said at least one outlet opening and/or of said direct aft of the bow line extending at least two legs have hydrodynamic shape in the longitudinal direction along portion or the entire of their perimeter. 6. Wave making energy absorber during vessel ' propulsion, in accordance to any of the above claims 1- wherein said passage defined for the flow of sea wat between said at least one inlet and said at least one outl opening comprises longitudinal l extending opening and/ slots and/or grooves of the desired number, form a arrangement, said openings and/or slots and/or groov effecting a balancing of pressures. 7. Wave making energy absorber during vessel ' propulsion, in accordance to any of the above claims 1-6 wherein a portion of said bow fwd mounted conductor and/o said aft of bow extending legs is incorporated into t vessel, thereby suitably shaping bow's geometry. 8. Wave making energy absorber during vessel ' propu 1 s i on, i n accordance to any of the above claims 1-7, sai absorber being mounted on a vessel in combination to th existing technology of bolbus bow. 9. Wave ma ing energy absorber during vessel ' propulsion, in accordance to any of the above claims 1-8, said passage for the flow of sea water between said a least one inlet opening up to at least one said outle opening of said either single conductor or conductor wit said legs extending on either side thereof has any linear o curved shape and is of a ci rcum erenci a 1 compact structure throughout its length. 10. Wave making energy absorber during vessel 's propulsion, in accordance to any of the above claims 1-9, said passage for the flow of sea water between said at least one inlet opening up to at least one said outlet opening of said either single conductor or conductor with said legs extending on either side thereof has any l inear or curved shape, and is entirely or partially opened on either of its vertically defined upper and/or lower sides. 11. Wave making energy absorber, during vessel's propulsion, in accordance to any of the above claims 1-10, wherein the vessel's bow line upon which said wave making energy absorber is mounted may be parallel to or in any desired inclination to the natural vertical line, the vessel being considered at sea calm condition. 12. Wave making energy absorber, during vessel 's propulsion, in accordance to any of the above claims 1-11, wherein if necessary said conductor is mounted onto the vessel by means of horizontally extending supporting elements with or without a hydrodynamic shape in the water flow di rect ion . AMENDED CLAIMS [received by the International Bureau on 25 September 1992 (25.09.92) ; original claims 1, 4, 6, 9 and 12 amended ; remaining claims unchanged ( 3 pages)] 1. Wave making energy absorber during vessel's propulsion, mounted forward of the bow and comprising an external conductor, which includes at least one inlet opening and at least one outlet opening, a passage being defined for the flow of sea water in between said inlet and said outlet opening, said conductor extending below or onto or below and above the water line level, where the sea water entering through said at least one inlet opening and exiting through said at least one outlet opening effects a reduction of the wave making losses. 2. Wave making energy absorber during vessel's propulsion, in accordance to above claim 1, said conductor extending aft of the bow line, being divided to at least two legs, each side reg having at least one inlet and at least one outlet opening for the sea water flow. 3. Wave making energy absorber during vessel's propulsion, in accordance to any of the above claims 1,2, wherein said conductor and/or said aft of the bow line at least two legs have a constant or divergent or convergent section or the combination of two or more sections in parts. 4. Wave making energy absorber during vessel's propulsion, in accordance to any of the above claims 2—3, comprising aft of the bow line at least two longitudinally extending said legs, where each of said legs includes at least one outlet opening of the sea water flow, said sea water flow being directly introduced into said at least two legs, extending on either side of the bow. 5. Wave making energy absorber during vessel's propulsion, in accordance to any of the above claims 1-4, where the entire length or a portion of length of said conductor extending from said at least one inlet opening to to said at least one outlet opening and/or of said directly aft of the bow line extending at least two legs have a hydrodynamic shape in the longitudinal direction along a portion or the entire of their perimeter. 6. Wave making energy absorber during vessel's propulsion, in accordance to any of the above claims 1—5, wherein said passage defined for the flow of sea water between said at least one inlet and said at least one outlet opening comprises openings and/or slots and/or guide ribs of the desired number, form and arrangement, said openings and/or slots and/or guide ribs effecting a balancing of pressures. 7. Wave making energy absorber during vessel's propulsion, in accordance to any of the above claims 1—6, wherein a portion of said bow fwd mounted conductor and/or said aft of bow extending legs is incorporated into the vessel, thereby suitably shaping bow's geometry. 8. Wave making energy absorber during vessel's propulsion,in accordance to any of the above claims 1-7, said absorber being mounted on a vessel in combination to the existing technology of bolbus bow. 9. Wave making energy absorber during vessel's propulsion, in accordance to any of the above claims 1—8, said passage for the flow of sea water between said at least one inlet opening up to at least one said outlet opening of said either single conductor or conductor with said legs extending on either side thereof has any linear or curved shape and is of a perimetrically compact structure throughout its length. 10. Wave making energy absorber during vessel's propulsion, in accordance to any of the above claims 1—9, said passage for the flow of sea water between said at least one inlet opening up to at least one said outlet opening of said either single conductor or conductor with said legs extending on either side thereof has a nv linear or curved shape, and is entirely or partially opened on either of its vertically defined upper and/or lower sides. 11. Wave making energy absorber, during vessel's propulsion, in accordance to any of the above claims 1-10, wherein the vessel's bow line upon which said wave making energy absorber is mounted may be parallel to or in any desired inclination to the natural vertical line, the vessel being considered at sea calm condition. 12. Wave making energy absorber, during vessel's propulsion, in accordance to any of the above claims 1-11, wherein if necessary said conductor is mounted onto the vessel by means of supporting elements with or without a hydrodynamic shape in the water flow direction .

Inventors: PETROMANOLAKIS E EMMANUEL, PETROMANOLAKIS, E., EMMANUEL
Applicants: PETROMANOLAKIS E EMMANUEL, PETROMANOLAKIS, E., EMMANUEL
Application year: 1992
Main classification: B63B1
IPC codes: B63B1