WO1996029475A1 - Swell reducing device - Google Patents
Swell reducing device Download PDFInfo
- Publication number
- WO1996029475A1 WO1996029475A1 PCT/FR1996/000408 FR9600408W WO9629475A1 WO 1996029475 A1 WO1996029475 A1 WO 1996029475A1 FR 9600408 W FR9600408 W FR 9600408W WO 9629475 A1 WO9629475 A1 WO 9629475A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- swell
- wave attenuating
- incident
- plate
- attenuating device
- Prior art date
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 16
- 238000010009 beating Methods 0.000 claims description 13
- 230000010355 oscillation Effects 0.000 claims description 10
- 230000008033 biological extinction Effects 0.000 claims description 5
- 230000002706 hydrostatic effect Effects 0.000 claims description 4
- 239000007788 liquid Substances 0.000 claims description 4
- 230000010363 phase shift Effects 0.000 claims description 3
- 238000011144 upstream manufacturing Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 238000013016 damping Methods 0.000 description 5
- 230000005284 excitation Effects 0.000 description 3
- 238000009434 installation Methods 0.000 description 3
- 230000001133 acceleration Effects 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 238000013519 translation Methods 0.000 description 2
- 230000014616 translation Effects 0.000 description 2
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000005188 flotation Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B3/00—Engineering works in connection with control or use of streams, rivers, coasts, or other marine sites; Sealings or joints for engineering works in general
- E02B3/04—Structures or apparatus for, or methods of, protecting banks, coasts, or harbours
- E02B3/06—Moles; Piers; Quays; Quay walls; Groynes; Breakwaters ; Wave dissipating walls; Quay equipment
- E02B3/062—Constructions floating in operational condition, e.g. breakwaters or wave dissipating walls
Definitions
- the present invention relates to a wave attenuating device.
- Attenuating device which is the subject of the present invention, for example, to preserve offshore installations or shipyards.
- the former have the drawback, in particular, of being cumbersome to implement and of high cost. In addition, they strongly disturb the marine flora and fauna. The second are difficult to use for swells of long wavelength.
- Such devices must therefore have large dimensions to have a significant effect on swells of long wavelength.
- they are generally attached to the bottom. Also, they have the disadvantage of being difficult to implement and of high cost.
- Another object of the present invention is to propose a swell attenuating device which lets sea currents pass and thus makes it possible to respect the ecological and sedimentological balances, the evacuation of pollutants discharged into the protected body of water and the integrity of the marine environment.
- An advantage of the present invention is that it makes it possible, in the event of tides, to monitor their level.
- An advantage of the present invention is that it has a low draft, which makes it possible to respect the aesthetics of the site.
- the present invention relates to a device for attenuating swell, said swell, called incident swell having a given mean direction of propagation, characterized in that it comprises beating means, semi-submersible, capable of recovering the energy of the incident swell and of generating, downstream of the device , a forced swell in phase shift relative to said incident swell and means for holding said beating means in place relative to the mean direction of propagation of the swell while leaving the device free in its vertical movements.
- Figure 1 describes, schematically, the principle of a wave attenuator device according to the invention.
- FIG. 2 shows, in a transverse view, an example of a wave attenuating device according to the invention.
- FIG. 3 is a front view of the swell attenuator device, shown in FIG. 2.
- Figure 4 is a top view, in section along the line IV-IV shown in Figure 3, the swell attenuator device shown in Figure 2 above.
- Figure 5 is a top view which shows an example of use of the wave attenuator device according to the invention.
- the present invention relates to a wave attenuating device. In general, it will find its application in particular in the control or use of watercourses, rivers, coasts or other maritime locations.
- the swell In a body of water, the swell generally propagates in a given direction defined, in particular, by the prevailing offshore winds, the waveguides formed by possible dikes, the trajectory of large ships whose wake generates swell, or whatever. It is, in fact a medium direction, the various incident swells having a distributed direction, substantially following a Gaussian shape, for example, at more or minus 45 ° around this fictitious general direction.
- incident wave 1 having a given mean direction of propagation 2, as defined above.
- forced swell 4 identified in long dotted lines, in the same direction 2 and of the same wavelength as the incident transmitted swell, identified in short dotted lines, but in opposition to the phases with respect to the latter, their effects will be canceled out and the calm will be obtained as symbolized by the line marked 5.
- the example of wave attenuating devices according to the invention is based on this principle.
- beating means 8 semi-submersible, capable of recovering the energy of the incident swell 1 that it is desired to attenuate and of generating, downstream of the device, a forced swell in phase shift relative to said incident swell 1.
- a swell is therefore generated, the effects of which, according to the principle set out above, will compensate for those of the incident swell.
- we will then tend towards obtaining a flat calm.
- such a device has the advantage of being autonomous. Indeed, it is the own beaters 8 which, by recovering the energy of the incident swell 1, ensure, by oscillating vertically, the production of the forced swell.
- downstream and upstream are defined according to the direction of propagation of the incident swell 1, this going, according to the arrow marked 2, from upstream to downstream.
- semi-submersible means that the beating means are provided floating near the surface of the water, as shown in Figure 2, and are not fixedly retained by the bottom.
- the swell attenuating device comprises means 9 for holding said beating means 8 in place relative to the mean direction of propagation of the incident swell 1, leaving the device free in its vertical movements.
- said means 9 for holding make it possible to retain the attenuator, in particular, in its horizontal translations and in its rotations around a vertical axis. They are also capable of preventing the rotations of said attenuator about a horizontal axis, that is to say, its possible roll movements. In other words, according to the present invention, only the vertical translations of the attenuator are authorized.
- the device acts, in fact, like a “mass-spring” system whose movements can be put into equation, by projection on a vertical axis, in the following form:
- M represents the mass of the device
- M a represents the mass of added water
- A represents the acceleration of the device
- a v represents the viscous damping
- a k represents the damping due to friction such as, in particular, the friction between the beater means 8 and the means 9 to maintain the latter in place
- a r • represents the damping of gravity wave due to the radiation corresponding to the energy radiated in the generated swell
- V represents the speed of the device
- H represents the hydrostatic stiffness
- K represents the stiffness of the means 9 for holding in place
- X represents the movement of the device
- F represents the excitation that the incident wave would exert on the device if the latter was fixed.
- the radiation damping should be as large as possible since it accounts for the energy of the swell generated and the stiffness of the device in front, as will be developed later, remained limited, it therefore appears necessary for the device to oscillate vertically that the sum M + M a is high.
- the beater means 8 comprise in particular a heavy plate 10.
- the latter is oriented, for example transversely to the mean direction of propagation of the incident swell 1.
- the heavy plate 10 has, according to the particular embodiment illustrated, in particular in FIGS. 2 and 3, ballasts 11, these being able to be more or less filled in order to adapt the mass of the device. They can also be used, if necessary, to adjust its draft as a function of the amplitude and / or direction of the swell, or the like. However, care must be taken to avoid the risks of liquid fairings.
- ballasts 11 Another advantage of the ballasts 11 is that they allow the device to be brought to the place where it is to be used by making it float stably.
- the heavy plate 10 is, in particular, rectangular in shape. According to other embodiments, it can also be, for example, square, oval or round.
- the plate 10 is arranged substantially horizontally, its largest dimension being perpendicular to the direction of propagation of the swell.
- the plate 10 is moreover oriented so that one of its edges is attacked by the incident swell at an average angle of 90 °.
- the device also comprises, for example, means 12 for increasing the mass of added water M a .
- means 12 for increasing the mass of added water M a are in particular transverse skirts 13, provided under the plate 10, in the vicinity of its long sides and / or, possibly, of its short sides.
- skirts 13 therefore delimit a volume of liquid 14 which, being confined under the swell attenuator, makes it possible to increase the forces in phase with acceleration and therefore the mass of water added.
- the skirts 13 also have, in particular, the advantage of attenuating swells of small wavelengths.
- the incident swells which it is desired to attenuate generally have, as for the direction, an average wavelength 3.
- we choose for the device a natural oscillation period as close as possible to the said average period of the incident swell 1.
- the natural period of the device remains slightly greater than said average period in order to prevent the generated swell 4 from undergoing an inversion and finding itself in phase with the incident transmitted swell.
- the device comprises, for example, means for adapting its own period of oscillation, in particular, as a function of the average period of the incident swell 1. They are constituted, in particular, by the heavy plate 10 provided for submerged, of so as to limit the hydrostatic stiffness of the device by reducing its surface in the vicinity of the water / air interface.
- T P 2 ⁇ . M + M a
- H that is to say the stiffness of the system. This decreases with the surface of the device at the water / air interface, the heavy plate 10 is submerged. However, as we saw above, the stiffness of the device must not be too low either if we want it to be able to oscillate.
- the device further comprises, for example a transverse veil 16, in particular vertical, semi-submerged, above the plate 10.
- the veil 16 can be provided substantially in the middle of said plate 10. It defines, on the side of the incident swell 1, a chamber called the upstream chamber 17 and, on the other side, a chamber called the downstream chamber 18.
- the web 16 can be provided either further back, or further forward so as to modulate the respective surface of the upstream 17 and downstream 18 chambers.
- the veil 16 has the advantages of also helping, in particular, to stop small swells. In addition, it makes it possible to break the speed and pressure fields of the incident swell 1. It can be noted that the skirts 13 and the veil 16 also make it possible to contribute to the attenuation of the swell by viscous dissipation.
- the energy withdrawal necessary for the oscillation between the upstream 17 and downstream chambers 18 is optimally distributed. For example, if good results have been obtained without the presence of sails 16 for swells of periods going from five to six seconds, performance is improved thanks to said sails 16, for swells whose periods range from seven to eight seconds.
- downstream chamber 18 constitutes a buffer tank.
- the water it stores makes it possible to dig the ridges and fill the troughs downstream.
- the substantially vertical veil 16 may have, in particular oblique veils 19 in the vicinity of its edges.
- the device also comprises, for example, semi-submerged sides 20, perpendicular to the transverse web 16, in the vicinity of the transverse edges of the plate 10. They contribute to ensuring hydrostatic stability of the device.
- the vertical edges of the flanks 20 in particular have chamfers 21. They participate, like the oblique sails 19, by smoothing the streamlines, in the hydrodynamic efficiency of the device.
- the device has a semi-submersible oscillating structure. According to the laws of hydrodynamics, there is therefore a period for which the excitation transmitted by the incident swell 1 is minimal. It is the extinction period T e defined by the vertical dimensions of the device and the ratio of the immersed surfaces.
- a weak extinction period is chosen so that it is closest possible periods for which the attenuator operates by reflection and / or dissipation, namely the short wavelengths.
- the device further comprise, for example, means for lowering its extinction period constituted in particular by controlling the ratio between the surface of the device at the liquid / air interface and the surface of the plate 10.
- the ratio between the flotation surface represented in hatched lines and the horizontal surface of the plate 10 is around 26%.
- the means 9 for holding the device in place consist, for example, of piles 23, not shown in FIGS. 2 and 3, on which the device is mounted to slide, substantially vertically.
- the piles 23 are in particular vertical, and open out through the plate 10. They are, for example, secured to the bottom.
- a flexible anchor can also be provided.
- the device comprises, above the veil 16, a panel 24 substantially horizontal. It makes it possible to constitute a pontoon. However, its dimensions must be adapted to the static stability and oscillation requirements of the device.
- the panel 24 has the advantage of limiting the effects of water sprays generated by the upstream chop.
- the attenuators are assembled, in particular, two to two, side by side and slide vertically, in particular, along substantially parallel piles 23.
- the overall direction of the attenuators is, in particular, perpendicular to the mean direction 2 of the incident swell 1.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Mechanical Engineering (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Revetment (AREA)
- Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
- Surgical Instruments (AREA)
- Ultra Sonic Daignosis Equipment (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU52778/96A AU709929B2 (en) | 1995-03-17 | 1996-03-18 | Swell-attenuating device |
DE69614839T DE69614839D1 (en) | 1995-03-17 | 1996-03-18 | THINNING REDUCTION DEVICE |
EP96909188A EP0815327B1 (en) | 1995-03-17 | 1996-03-18 | Swell reducing device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR95/03377 | 1995-03-17 | ||
FR9503377A FR2731724B1 (en) | 1995-03-17 | 1995-03-17 | SWELL ATTENUATOR |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1996029475A1 true WO1996029475A1 (en) | 1996-09-26 |
Family
ID=9477321
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FR1996/000408 WO1996029475A1 (en) | 1995-03-17 | 1996-03-18 | Swell reducing device |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0815327B1 (en) |
AU (1) | AU709929B2 (en) |
DE (1) | DE69614839D1 (en) |
ES (1) | ES2163619T3 (en) |
FR (1) | FR2731724B1 (en) |
TR (1) | TR199700970T1 (en) |
WO (1) | WO1996029475A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GR1003786B (en) * | 2000-12-28 | 2002-01-30 | Θαλασσια Μηχανικη Αε | Floating, vertically anchoring wave absorbers |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1417153A (en) * | 1964-07-24 | 1965-11-12 | Transp Et De La Valorisation D | Swell attenuation device and its effects |
US3487645A (en) * | 1968-08-21 | 1970-01-06 | Litton Systems Inc | Wave damping device |
DE1784588A1 (en) | 1968-08-22 | 1971-10-07 | Grenobloise Etude Appl | Floating breakwater |
FR2532345A1 (en) * | 1982-09-01 | 1984-03-02 | Rech Etu Oceanographiques | Floating anti-swell boom |
GB2170249A (en) * | 1985-01-24 | 1986-07-30 | Principia Rech Dev | Attenuation of swell in liquids |
-
1995
- 1995-03-17 FR FR9503377A patent/FR2731724B1/en not_active Expired - Lifetime
-
1996
- 1996-03-18 TR TR97/00970T patent/TR199700970T1/en unknown
- 1996-03-18 AU AU52778/96A patent/AU709929B2/en not_active Ceased
- 1996-03-18 ES ES96909188T patent/ES2163619T3/en not_active Expired - Lifetime
- 1996-03-18 EP EP96909188A patent/EP0815327B1/en not_active Expired - Lifetime
- 1996-03-18 WO PCT/FR1996/000408 patent/WO1996029475A1/en active IP Right Grant
- 1996-03-18 DE DE69614839T patent/DE69614839D1/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1417153A (en) * | 1964-07-24 | 1965-11-12 | Transp Et De La Valorisation D | Swell attenuation device and its effects |
US3487645A (en) * | 1968-08-21 | 1970-01-06 | Litton Systems Inc | Wave damping device |
DE1784588A1 (en) | 1968-08-22 | 1971-10-07 | Grenobloise Etude Appl | Floating breakwater |
FR2532345A1 (en) * | 1982-09-01 | 1984-03-02 | Rech Etu Oceanographiques | Floating anti-swell boom |
GB2170249A (en) * | 1985-01-24 | 1986-07-30 | Principia Rech Dev | Attenuation of swell in liquids |
Also Published As
Publication number | Publication date |
---|---|
EP0815327B1 (en) | 2001-08-29 |
EP0815327A1 (en) | 1998-01-07 |
ES2163619T3 (en) | 2002-02-01 |
FR2731724A1 (en) | 1996-09-20 |
DE69614839D1 (en) | 2001-10-04 |
AU5277896A (en) | 1996-10-08 |
TR199700970T1 (en) | 1998-02-21 |
AU709929B2 (en) | 1999-09-09 |
FR2731724B1 (en) | 1997-06-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2997257B1 (en) | Offshore wind turbine on a floating mount comprising a combination of shock-absorbing means | |
EP1650355B1 (en) | Device for mitigation of a wave | |
FR2967642A1 (en) | OFFSHORE WIND POWER DEVICE WITH PARTICULAR SEMI-SUBMERSIBLE FLOAT | |
EP0282479B1 (en) | Method and device for attenuating the sea swell | |
FR2980245A1 (en) | DEVICE FOR RECOVERING ENERGY FROM MARINE OR WATERCOURSE CURRENTS | |
EP0815327B1 (en) | Swell reducing device | |
EP0381572B1 (en) | Device for attenuating sea swell | |
FR2968020A1 (en) | Floating breakwater for use on rubble-mound jetty for forming structure that attenuates waves generated on surface of e.g. sea, has ballasting unit for moving part of volume of water between lower surface of box and surface of unit | |
FR2576337A1 (en) | SWELL ATTENUATOR | |
EP4259519A1 (en) | Device for continuously gathering floating waste on the surface of an aqueous medium to optimise the recovery thereof | |
EP0956394B1 (en) | Improvements to fixed partially immersed caisson dikes | |
FR2758147A1 (en) | Semi=submerged caisson=type breakwater | |
FR2729981A1 (en) | Wave protection barrier | |
EP3653793B1 (en) | Reduction of the reflection coefficient of a vertical wall in a port | |
EP0346554B1 (en) | Structure for the attenuation of waves | |
FR2817887A1 (en) | PROTECTIVE DEVICE FOR MITIGATING THE EFFECTS OF SWELL IN AN AREA OF WATER TO BE PROTECTED, A PORT SITE FOR EXAMPLE | |
WO2018019525A1 (en) | Floating support structure comprising a floater and a damping plate with a cross-section that varies with depth | |
FR3073258A1 (en) | FLOATING HYDROELECTRIC PLANT FOR SHALLOW RIVERS | |
FR2695666A1 (en) | Method of dissipating wave energy along coastlines - using perforated flat slabs submerged horizontally at specified distance from average surface height of sea | |
Bergmann et al. | Digue innovante en caissons multichambres: Fonctionnement et sollicitations hydrauliques | |
EP0379415A1 (en) | Anchoring device with a stabilization component | |
Paotonan et al. | The Effect of Hanging Sheet Pile Breakwater’s Draft Relative on Wave Transmission Coefficient (Kt) in Irregular Wave | |
FR3092627A1 (en) | Turbine. | |
WO2021079065A1 (en) | Device for attenuating an ocean gravity wave | |
WO2004016859A1 (en) | Device for protecting seacoasts |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AM AU BB BG BR BY CA CN CZ EE GE HU IS JP KG KP KR KZ LK LR LT LV MD MG MN MX NO NZ PL RO RU SG SI SK TJ TM TR TT UA US UZ VN |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): KE LS MW SD SZ UG AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 1996909188 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 97/00970 Country of ref document: TR |
|
WWP | Wipo information: published in national office |
Ref document number: 1996909188 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: CA |
|
WWG | Wipo information: grant in national office |
Ref document number: 1996909188 Country of ref document: EP |