RU2309081C1 - Large sea buoy at preset wave resistance and stability - Google Patents

Abstract

FIELD: navigational aids for deep-water areas at approach to ports and harbors subjected to considerable swell.

SUBSTANCE: vertical size of proposed buoy exceeds its diameter by 3-5 times; buoy body has watertight damper-neutralizer at depth of 2-6 m from surface; its volume is no less than 10% of main body volume. Damper has upper and lower taper surfaces. Outer edges of upper surface of damper-neutralizer are rounded-off at radius of 0.05-0.1 of radius of damper horizontal surface. Solid ballast arranged in lower part of buoy body is made in form of stacked disks at diameter D_s.b. equal to 1.2-1.4 of average diameter of immersed body D_im.b. ; averaged diameter of main body and its total depth T_im.b., sizes of damper-neutralizer of wave load, mass of solid ballast and buoy displacement are determined depending on preset useful load, rated swell, depth of laying the buoy, requirements for metacentric height and required degree of neutralization of wave disturbing forces.

EFFECT: reduced mass of buoy at preset wave resistance.

2 dwg

Description

The invention relates to navigational support for large-displacement deep-water fairway sea buoys on the approach to ports and harbors subject to significant sea disturbance. It can also be used for autonomous buoy stations (ABS), monitoring the marine environment, as well as other special functions.

Famous Large Sea Buoys (BMB) (Guide to Navigation Equipment. Part 1, L. GUINO, 1983) are barrel-shaped buoyancy with a diameter of 2.5 ÷ 2.6 m and a total hull height of 2 ÷ 2.5 m. Above it rises the mast of the truss type, which houses a light-optical apparatus (SOA), radar reflectors (RLO) and howler. On the ABS, the mast also houses equipment for measuring air parameters and waves, as well as a radio transmitting antenna. The main disadvantage of BMB and ABS is the irrational architectural form, which entirely perceives wave disturbing forces and moments. The result of this is the increased vertical and angular pitching of the BMB and ABS and the frequent breaks of the bonds holding them.

A technical solution is known to the patent of the Russian Federation 2011599 (Razumeenko Yu.V., Pylnev Yu.V. Semi-submersible base of an offshore structure, Bulletin No. 8 of 04/30/94) - analogue. In accordance with this patent, to neutralize the vertical wave perturbing forces, the buoy must be made in the form of a long semi-immersed cylinder with a total length of at least 1.35-1.5 of the estimated wave height h _p , while at a depth of T _d ≥ 1.2 of the calculated amplitude of wave A _p = 0.5h _{p the} buoy must have a flat or volume passive active damper (LAD), the dimensions of which are determined by the calculated wavelength λ _p . The buoy, made according to the recommendations of this patent, will have 4-6 times less tearing forces, as well as reduced vertical and angular pitching compared to buoys of traditional shapes.

However, the high displacement cylindrical body, especially when it is made of steel, creates stability problems, because of which it is necessary to use heavy solid ballast and increase the displacement of the buoy.

The closest in essence to the present invention is a technical solution according to the patent of the Russian Federation No. 2180544 (Floating warning sign of increased wave resistance, bull. No. 28 from 10.10.2002) - prototype.

In accordance with the well-known technical solution, the surface displacement part of the PPZ is made 1–1.5 m high, but not less than half the amplitude of the calculated wave; light-emitting apparatus (SOA) and radar reflectors (RLO) rise to the required height above this surface part on the mast structures , the battery is located in the lower part of the housing, while the solid ballast is attached to its bottom and is made in the form of a flat disk with a diameter of D _tb = (1.8-2.0) D _pc , where D _pc is the average diameter of the immersed part of the housing, completed of the cones or the diameter of the cylindrical body, and its mass is determined by the value of the specified metacentric height h = (0.25-0.30) m, at a distance from the waterline of 1.2-1.3 of the calculated amplitude, the PPZ waves have passively active dampers, at the same time, the dampers have a bevel at an angle of 20-30 ° to the horizon, which ensures their unequal efficiency when the wave is raised up and down.

This technical solution partially adapts the recommendations of patent No. 20111599 to the features of the buoys. However, the description and claims of the prototype patent have the following disadvantages:

- A well-known technical solution is rigidly tied to the value of metacentric height h = 0.25-0.3 m. However, the requirements for it for buoys of different types and purposes can be different. And, in addition, the value of h significantly affects the angular rolling of the buoy.

- The diameter of the TB disk D _tb = (1.8-2.0) D _pc assigned too large, which may be disadvantageous for structural reasons.

- The decrease in the height of the watertight surface part compared to the underwater part is compensated for by the divergence in the effectiveness of PADs due to beveling down their surface, however, the concept of “beveling” does not accurately reflect the essence of the proposal - in fact, PAD has a conical surface.

- The formula of the patent prototype does not stipulate the dimensions of the dampers, it is assumed that they comply with the recommendations of the 2011599 patent for the complete structural neutralization of vertical wave forces. This leads to large sizes of dampers, which for design reasons may be unacceptable, and for specific operational requirements - unnecessary.

- It is impossible to independently meet the buoyancy and stability requirements of the buoy with a predetermined draft and metacentric height without taking into account the weight and buoyancy of the PAD, the buoyancy of which can be comparable with the buoyancy of the main body. An additional action algorithm is required.

The purpose of the invention is the provision of BMB of a given degree of wave resistance and stability, reducing wind load while reducing its volume and mass. These goals are achieved by the fact that in a semi-submersible vertically oriented housing ППЗ, including the immersed part with a total draft T _{pc of} at least 1.35-1.5 of the calculated wave amplitude A _r and covering the case with a passive-active damper, the upper edge of which is removed from the unperturbed surface at the value of T _d not less than (1.2-1.3) of the calculated wave amplitude, a waterproof surface part of a height of 1-1.5 m, but not less than half A _{p of the} calculated wave amplitude located above it with the help of the mast structure of the RLO and SOA, rechargeable battery laid in the lower part of the PPZ, and a solid ballast made in the form of a flat disk rigidly connected to the lower part of the body, the damper is made volumetric, with a displacement of at least 10-15% of the displacement of the main vertically oriented body, the upper and lower surfaces of the damper are conical with an inclination the upper generatrix to the horizon is at least 20-30 °, and the lower one is 1.5-2 times less than the upper one, the outer edges of the upper surface of this damper are rounded with a radius of 0.05-0.1 of the radius of its horizontal projection smoothly evodyaschee conical surface in a vertical extending to the bottom of the conical surface, SOA and RLS lifted above the free water surface at a height of not less than 3.5-5 m, the solid ballast made in the form of flat discs on-board diameter D _TB = (1,2 ÷ 1 4) D _pc , where D _pc is the average diameter of the submerged part of the body made of cones, or the diameter of the cylindrical body, these disks on studs are attached to the main, main disk, rigidly connected (for example, by welding or bolts) to the bottom of the BMB body lower conical surface of the surround empfera, the body of the buoy and the radical drive solid ballast rigidly (e.g., welding) are connected by vertical with brackets that perform the role of reinforcement damper linkages and vertical dampeners, reducing the angular oscillations of the buoy at a wavelength, wherein the averaged diameter of the submerged part of the main body D _pc, its overall penetration T _pc , the dimensions of the volume damper, the mass of the required solid ballast and the displacement of the BMB as a whole are determined on the basis of a given payload (mass of the battery, SOA, radar, etc.), estimated ballast and the sea, setting depth, requirements for metacentric height and the necessary degree of neutralization of the wave perturbing forces from the sequential solution of the following system of algebraic equations

- Equations of mass and buoyancy BMB

where ρ = 1.01 ÷ 1.025 t / m ³ is the density of sea water;

V _pc - the volume of the immersed part of the main body, m ³ ;

V _od - displacement volume of the damper, depending on its shape and size, m ³ ;

m _ng is the mass of freights independent of the size of the BMB, given or pre-accepted, for example, the masses of the light-optical apparatus and the battery, t;

m _zg is the mass of cargo, depending on the size and shape of the BMB, for example, the main body, damper, brace, t;

m _tb is the mass of solid ballast together with the mass of BMP-holding bonds, which depend on the depth of the formulation site, t;

ρ _tb - the density of the material of solid ballast and holding bonds, a large density of water, t / m ³ ;

- редукционный коэффициент, учитывающий потерю веса твердого балласта и якорь-цепи в воде;

- reduction coefficient taking into account the weight loss of solid ballast and anchor chain in water;

- The specified range of permissible changes in metacentric height

where z _c is the position of the height of the center of buoyancy of the water-scattering volumes of the BMB hull with a draft of T _pc , damper, brace, m;

r is the metacentric radius;

z _g is the height position of the BMB of the center of mass of all goods: the hull, together with the damper, solid ballast, anchor chain, and others, which are balanced by the buoyancy of the buoy during draft T _pc .

- The equation for choosing the dimensions of the volumetric conical pad

where 0 <n≤0.5 is the neutralization coefficient of the wave perturbing forces, equal to 0 when they are completely neutralized and 0.5 when partial;

S _pc - the average horizontal sectional area of the submerged body when it is made of cones or the horizontal sectional area of the cylinder, m ² ;

T _pc - the estimated draft of the submerged BMP body, assigned in the interval (0.6 ÷ 1.2) of the calculated wave amplitude A _p , while a lower value of T _pc corresponds to a larger value of the neutralization coefficient n, m;

k _pc is the coefficient of the attached mass of the submerged body during acceleration of water particles in the wave directed upward, taken within 0.3 ÷ 0.4;

S _od - the area of the horizontal projection of the conical volumetric damper, m ² ;

k _od - the added mass coefficient of the volume damper, referred to ρV _od taken in the range of 0.6 ÷ 0.8;

T _od - removal from the surface of the middle of the upper conical surface of the volume damper, assigned in the interval (0.6 ÷ 0.8) T _pc ;

N _od - the average height of the volume damper assigned in the interval (0.2 ÷ 0.4) T _pc , m;

λ _p - estimated wavelength, m

Figure 1 shows the BMB, the waterproof part of which is made of truncated cones connected by large bases, and in figure 2 is the same BMB, based on a vertical circular cylinder and a volume damper. These BMBs include the submerged part 1 in the form of a vertical cylinder or composite cones with a draft of T _pc . The surface displacement part 2 may be cylindrical or conical in shape. SOA 4 and RLO 5 rises above it on mast structures 3 to a predetermined height.

Volumetric dampers 6 are supported by crosswise vertical flat brackets 7, extending from the lower conical surface of the damper to the main disk of the solid ballast 8. These brackets are rigidly connected (for example, by welding) to the damper, the BMP body and the main disk of the solid ballast. The other 2-4 discs 9 are attached to it on studs. This makes it possible to ensure buoy buoy along a predetermined waterline when changing the depth of the position and setting in connection with this the weight of the anchor chain. Down from the bottom there is a shank 10 to which a retaining PPZ connection (not shown) is attached.

для волн 3% обеспеченности и

для волн 1% обеспеченности.Excitement is a random process, but there are statistical relationships between average heights and wavelengths

for waves of 3% coverage and

for waves of 1% coverage.

для волн 3% или 1% обеспеченности и получить для принятых Т_пк и Т_од условия на выбор площади горизонтального сечения S_од и высоты Н_од объемного демпфера, нейтрализующие с коэффициентом n квазигидростатическую возмущающую силуUsing these ratios and the above recommendations for the selection of T _pc and T _od and assigning, depending on the stringency of the requirements for moderate pitching, T _pc = (0.6-1.2) A _p = (0.3-0.6) h _p and T _od = (0.7-0.8) T _pc , you can pre-calculate

for waves of 3% or 1% coverage and to obtain, for the accepted T _pc and T _od, conditions for choosing the horizontal section area S _od and the height H _{od of the} volume damper, which neutralize the quasi-hydrostatic disturbing force with coefficient n

where k _od - the coefficient of the attached mass of the volume damper with conical upper and lower surfaces, depending on its shape and lying in the range of 0.6-0.8;

a and b are the coefficients corresponding to the calculated wave height of 1% and 3% of the security indicated above;

k _pc - the coefficient of the attached mass of the submerged main body, lying in the range of 0.3-0.4.

By assigning S _od ≈ (1.5-1.8) S _pc , one can find H _od from (4), or, according to the designation appointed by the design considerations H _od ≤ (0.2-0.3) T _pc, find S _od .

The proposed technical solutions for finding the size and shape of the BMB of a given wave resistance and stability can be implemented during their design in the following sequence:

1. The area and depth of setting are specified, the estimated sea score is indicated, and a coefficient of neutralization of wave loads at which BMP and ASB should function normally is indicated, general and special requirements are indicated. This makes it possible to assign the calculated wave height h _p and its length λ _p , as well as the draft of the submerged body T _pc , the height of the surface part of the body H _nk .

2. The payload is set: the mass of SOA, RLO, the battery and m _{ng is} determined.

3. Based on the analysis of the requirements of the assignment, the architectural type (Figs. 1, 2) of the case material and its thickness is selected, the damper depth T _od = (0.7-0.8) T _pc is assigned.

4. The proportion of the volumetric PAD displacement from the displacement of the submerged part of the main body is assigned V _od = r _od · V _pc , r _od ≈0.15-0.4.

5. Based on the requirements for metacentric height, the limits of its permissible values h ₁ <h _back <h _{2 are} indicated.

6. Using these prototype buoys, approximate expressions are found for mass-dependent buoy sizes, for example, hulls, chain anchors, and the proportion of solid ballast is assigned. The result is an expression like

where p ' _cr , p' _nap , p ' _yaz , p' _tb are the shares in the first approximation of the mass of the hull, filler, anchor chain and solid ballast from the displacement of the main body of the buoy and PAD.

7. Taking into account V _pc = S _pc · T _{pc, the} equation of mass and buoyancy is compiled to determine, as a first approximation, the averaged cross-sectional area of the submerged body S _pc

From his solution, with the precipitate already assigned, T _pc is determined to a first approximation S ' _pc , D' _pc .

.8. According to the area of the reduced section of the main body S _pc already determined in the first approximation and assigned according to the given point T _pc , as well as the value "a" and "b" defined above, the wave-resistance equation (4) is compiled and solved and the horizontal section area S _od damper, its height H _od and volume. This clarifies the proportion of PAD assigned in the first approximation

.

9. After this, the cycle is repeated according to claims 5 to 8 and the compatibility of the equations of mass and buoyancy (1) and wave resistance (4) is checked, the proportion of PAD and its dimensions are specified.

10. According to this agreed approximation, a BMB sketch is developed, thicknesses of the hull and PAD sheets are assigned, strength calculations are made, and displacement, mass of the hull, filler, sizes and masses of the damper, brackets, main and stacked disks of solid ballast are determined to ensure swimming BMB on a wave-resistant waterline. According to them, it is specified in the II approximation for the case with a damper and disks of solid ballast the shares p '' _kp , p '' _nap , p '' _yaz , p '' _{tb the} part of the anchor chain p '' _{yaz is specified} taking into account the maximum setting depth, and also the shares of the primary and composing disks of solid ballast.

11. Equation (6) and (4) are compiled in the II approximation and S ″ _pc , D ″ _pc are refined.

12. The sketch of the BMB and all its elements is specified, the displacement, the center of mass, buoyancy, the metacentric radius of the BMB are calculated in the II approximation, the metacentric height h is calculated and compared to the _back h. If it falls within the specified interval, further development of structures is underway, the load is being specified, and the weight of the BMB with additional disks of solid ballast and an anchor chain assembly m _{BMB is} determined. If the stability condition is not satisfied, the mass of additional disks of solid ballast increases or decreases, items 6 ÷ 11 are repeated and S '' _pc and S '' _od are specified.

13. The total displacement of the BMB is determined taking into account the displacement of the PAD, brackets, the main disk of the solid ballast, V according to the predetermined wave-resistant waterline and is compared with the mass of the BMB assembly m _BMB . Once again, the satisfaction of stability requirements is verified. If the difference ρV _BMB -m _BMB without damage to the operation of the BMB at different depths and the specified interval of the permissible measurement of metacentric height can be compensated by removable disks, the process can be considered completed. If this is not possible, the equation of mass and buoyancy is compiled and the corresponding value S '' _pc is determined and the cycle is repeated according to items 6 ÷ 11.

The proposed technical solution is fundamentally different from the prototype and analogue in the following indicators:

- it does not set the task of completely neutralizing the wave forces, but introduces a coefficient of their neutralization 0 <n≤0.5, which allows only to reduce the largest calculated separation forces on the anchor chain, but the introduction of a neutralization coefficient, for example, n = 0.5, allows to significantly reduce the draft of the buoy from 1.35-1.5 of the calculated amplitude A _p to (0.6-0.8) A _p and the total vertical size of the BMB, as well as the diameters of the disks of solid ballast and damper; this broadens the range of application of this technical solution for shallow areas, but the strength of the holding bonds in this case should be greater;

- volume conical PAD has a significant advantage over sheet conical, because at a given load, it can take on part of the required BMB buoyancy and thereby reduce the area of the waterline of the main body S _pc , the consequence of this is:

- a decrease in the main quasistatic wave component and a decrease in the total displacement (For BMB and ASB this is an important advantage);

- the upper conical surface of the PAD has rounding, which reduces the stall of the flow during oscillations of the wave surface.

- solid ballast is made up of a main disk, rigidly welded to the lower part of the body, and several removable disks, on studs, attached to the main one; this ensures the installation of BMB at different depths with different lengths of the anchor chain to ensure the necessary precipitation for its wave resistance;

- the vertical and horizontal dimensions of the main body and volume damper BMB, displacement and the amount of solid ballast is determined by the method of successive approximations in terms of a given payload, setting depth, estimated sea level, the adopted coefficient of neutralization of wave forces and the range of metacentric height h _min <h <h _max , which, depending on the requirements for angular pitching, will differ from h = 0.25-0.3 m in the prototype.

Patent search did not reveal such technical solutions. Therefore, it meets the criterion of novelty.

The proposed technical solution for BMB and large displacement ABS also meets the criterion of a significant positive effect. Compared with the closest prototype, the PPZ with a plate damper with a bevel it contains a volume damper of a more perfect shape, the volume and dimensions of this damper, together with the dimensions of the body, are coordinated with the necessary degree of compensation of wave forces and, in addition, it is possible to ensure stability in the set for a specific buoy limits. The internal volumes of the proposed PAD can be used to place payloads, which, when fixing the latter, can reduce the diameter of the main body, reduce the disturbing wave forces, and obtain a significant gain in the displacement and efficiency of the BMP and ABS.

Claims (1)

A large sea buoy of a given wave resistance and stability, including a vertically oriented body made of a cylinder or truncated cones with a total draft T _{pc of} at least 1.35-1.5 of the calculated wave amplitude A _p , a passively active damper, the upper edge of which is removed from the undisturbed surface by a value of T _d not less than (1.2-1.3) A _p , and a watertight surface part 1-1.5 m high, but not less than half A _p with a light-optical apparatus and radar reflectors located above it with the mast structure and howl , a battery located in the lower part of the housing, and a solid ballast made in the form of flat stacked disks rigidly connected to the lower part of the housing, characterized in that the damper is made with a volume displacement of at least 10-15% of the displacement of the main vertically oriented body, upper and the lower surface of the damper are conical with an inclination of the upper generatrix to the horizon by less than 20-30 °, and the lower one is 1.5-2 times smaller than that of the upper one, the outer edges of the upper surface of this damper are rounded with a radius of 0.05-0.1 of the radius of its horizontal projection, which smoothly translates the conical surface into a vertical cylindrical one, going to the lower conical surface, the light-optical apparatus and radar reflectors are raised on the mast above the free surface to a height of at least 3.5-5 m, solid ballast is made in the form of stacked flat disks with a diameter of D _tb = (1.2-1.4) D _pc , where D _pc is the average diameter of the main submerged body made of truncated cones, or the diameter of a cylindrical body, these disks are mounted on studs to fundamentally To the main root disk, rigidly connected (for example, by welding or bolts) to the bottom of the hull of the large sea buoy, the lower conical surface of the volume damper, the main body and the root disk of the hard ballast are rigidly (for example, in welding) connected by vertical flat brackets, which serve as reinforcing the damper ties and vertical flat dampers, reducing the angular oscillations of a large sea buoy on the wave, while the averaged diameter of the submerged part of the main body, its total depth T _pc , volume, height and the horizontal projection area of the damper, the mass of solid ballast required and the displacement of a large sea buoy as a whole are determined based on a given payload, estimated sea level, setting depth, metacentric height requirements and the necessary degree of neutralization of wave perturbing forces from a sequential solution of the following system of algebraic equations: - Equations of mass and buoyancy of a large sea buoy

where ρ = 1.01-1.025 t / m ³ is the density of sea water; V _pc - the volume of the immersed part of the main body, m ³ ; V _od - the displacement volume of the damper, depending on its shape and size, m ³ ; m _ng is the mass of cargo independent of the dimensions of a large sea buoy, given or pre-accepted, for example, the masses of a light-optical apparatus and a battery, t; m _zg - weight dependent on the size and shape of a large sea cargo buoy, for example, the main body, damper, brace, t; m _tb is the mass of solid ballast together with the mass of bonds holding a large sea buoy, which depend on the depth of the location, t; ρ _tb — density of material of solid ballast and bonds holding large sea buoy, high density of water, t / m ³ ;

- reduction coefficient taking into account the weight loss of solid ballast and anchor chain in water; - The specified range of permissible changes in metacentric height h _max > h _ass = z _c + rz _g > h _min , where z _c is the position of the height of the center of buoyancy of the displacement volumes of the BMB hull when the draft is T _pc , damper, brace, m; r is the metacentric radius; z _g - the height position of the large sea buoy of the center of mass of all goods: the hull, together with the damper, solid ballast, anchor chain and others, which are balanced by the buoyancy of the buoy during the draft T _pc , Equation for choosing the dimensions of a volumetric conical passive-active damper

where 0 <n≤0.5 is the neutralization coefficient of the wave perturbing forces, equal to 0 when they are completely neutralized and 0.5 when partial; S _pc - the average horizontal sectional area of the submerged body when it is made of cones or the horizontal sectional area of the cylinder, m ² ; T _pc - the estimated draft of the submerged hull of a large sea buoy, assigned in the range of 0.6 ÷ 1.2 of the calculated wave amplitude A _p , while a lower value of T _pc corresponds to a larger value of the neutralization coefficient n, m; k _pc is the coefficient of the attached mass of the submerged body during acceleration of water particles in the wave directed upward, taken within 0.3 ÷ 0.4; S _od - the area of the horizontal projection of the conical volumetric damper, m ² ; k _od - the added mass coefficient of the volume damper, referred to ρV _od taken in the range of 0.6 ÷ 0.8; T _od - removal from the surface of the middle of the upper conical surface of the volume damper, assigned in the interval (0.6 ÷ 0.8) T _pc ; N _od - the average height of the volume damper assigned in the interval (0.2 ÷ 0.4) T _pc , m; λ _p is the calculated wavelength, m

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