Simulation scale design method for seafloor slender flexible pipeline component

Abstract

The invention discloses a simulation scale design method for a seafloor elongated flexible pipeline component, which comprises the following steps of: constructing a hydraulic similarity condition calculation model and a structural dynamic similarity condition calculation model on the basis of hydraulic similarity and structural dynamic similarity between analogue simulation tests and prototypes; according to the method, hydraulic similar conditions and structural power similar conditions are correspondingly calculated, and the hydraulic similar conditions and the structural power similar conditions are ensured to be met when the seafloor elongated flexible pipeline test component is subjected to an analogue simulation test, so that sufficient similarity between the analogue simulation test and a prototype can be effectively ensured; therefore, the prototype data capable of reflecting the motion law of the prototype can be accurately obtained.

Description

Technical Field

[0001] The invention relates to a simulation scale design method for a submarine slender strip-type flexible pipeline component. Background Art

[0002] Slender, rigid or flexible submarine structures are common man-made marine structures. Typical examples include flexible submarine optical cables and rigid submarine oil and gas pipelines. Due to the complex seabed topography and wide-area installation, these structures often face extremely complex and unpredictable sea conditions, significantly complicating their safety and maintenance. Examples include the Sino-US trans-Pacific submarine optical cable, which even spans the entire Pacific Ocean. Another example is the Nord Stream natural gas pipeline from Russia to Germany, which spans over 1,000 kilometers across the Baltic Sea.

[0003] Given the complex and ever-changing scenarios faced by these slender flexible or rigid pipeline components, as well as the significant investment and complex construction process involved, extensive early-stage laboratory testing is often required to demonstrate their feasibility and reliability. Typically, stress vibration in slender pipeline components is a key cause of component damage. Therefore, full-scale simulation of seabed conditions and components is required to observe and examine the oscillation damage process of slender pipeline components.

[0004] However, due to objective conditions such as indoor test scenarios, size, and investment, slender strip pipeline components are often difficult to conduct 1:1 indoor tests. Instead, they often need to be scaled based on the scale effect to meet the requirements of laboratory test conditions. Among them, the full-scale scaling problem of rigid components is relatively simple, and therefore, the scaling calculation of slender strip components is also relatively simple. However, the scaling problem of flexible slender strip pipeline components is relatively complex. It not only involves the interaction between the solid and liquid phases, but also involves the hydroelastic motion of the flexible slender strip profile model. This also makes the scaling calculation method for rigid components unsuitable for flexible components. Summary of the Invention

[0005] The present invention aims to provide a method for designing a simulated scale of a submarine slender strip flexible pipeline component, thereby solving the problem of scaling the flexible slender strip pipeline component under realistic simulation of actual sea conditions.

[0006] In order to achieve the above technical objectives, the present invention will adopt the following technical solutions:

[0007] A simulation scale design method for a submarine slender strip flexible pipeline component includes the following steps:

[0008] Step 1: Based on the hydraulic similarity and structural similarity criteria, a hydraulic similarity condition calculation model and a structural dynamic similarity condition calculation model for the simulation test of the submarine slender strip flexible pipeline test component are constructed, wherein:

[0009] A hydraulic similarity condition calculation model is used to calculate hydraulic similarity conditions, including length similarity scale, time similarity scale, velocity similarity scale, acceleration similarity scale, mass similarity scale, momentum similarity scale, and energy similarity scale;

[0010] The structural dynamic similarity condition calculation model is used to calculate the structural dynamic similarity conditions, including the bending stiffness of the submarine slender strip flexible pipeline test component and the wall thickness of the submarine slender strip flexible pipeline test component under the bending stiffness similar to that of the submarine slender strip flexible pipeline prototype;

[0011] Step 2: Based on the current status of simulation tests of submarine slender flexible pipeline test components, determine the length similarity scale used in the simulation test, and calculate the various test parameters of the simulation test according to the hydraulic similarity condition calculation model and the structural dynamic similarity condition calculation model constructed in Step 1;

[0012] Step 3: Based on the test parameters calculated in step 2, a submarine elongated flexible pipeline test component is manufactured, and it is ensured that the manufactured submarine elongated flexible pipeline test component meets the above-mentioned hydraulic similarity conditions and structural similarity conditions when conducting the simulation test;

[0013] Step 4: Load the manufactured submarine slender strip flexible pipeline test component into the simulation test equipment, and install corresponding monitoring instruments or equipment on the submarine slender strip flexible pipeline test component according to the test requirements;

[0014] Step 5: Conduct a simulation test of the submarine slender strip flexible pipeline test component according to the test conditions, and save the data monitored by the monitoring instrument or equipment into a database file;

[0015] Step 6: According to the test requirements, statistically analyze the corresponding monitoring database files and analyze the motion law data of the flexible slender strip pipeline component model reflected by the monitoring data;

[0016] Step 7: Based on hydraulic similarity conditions and structural similarity conditions, the motion law data of the submarine slender strip flexible pipeline test component obtained in step 6 is reversely converted into the motion law data of the submarine slender strip flexible pipeline prototype.

[0017] Preferably, in step 1, the hydraulic similarity condition calculation model includes a length similarity scale calculation model;

[0018] The length similarity scale calculation model is used to calculate the length similarity scale of submarine slender flexible pipeline test components. Specifically:

[0019] λ l =L p / L m ;

[0020] Where, L p L is the length of the submarine slender flexible pipeline prototype. m It is the length dimension of the submarine slender strip flexible pipeline test component.

[0021] Preferably, in step 1, the hydraulic similarity condition calculation model further includes a time similarity scale calculation model;

[0022] The temporal similarity scale calculation model is used to calculate the temporal similarity scale λ of the simulation test t , λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

[0023] Preferably, in step 1, the hydraulic similarity condition calculation model further includes a velocity similarity scale calculation model;

[0024] The speed similarity scale calculation model is used to calculate the speed similarity scale λ of the simulation test v , λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

[0025] Preferably, in step 1, the hydraulic similarity condition calculation model further includes an acceleration similarity scale calculation model;

[0026] The acceleration similarity scale calculation model is used to calculate the acceleration similarity scale λ of the simulation test a , λ l A similar scale showing the length of a submarine slender flexible pipeline test component;

[0027] Preferably, in step 1, the hydraulic similarity condition calculation model further includes a mass similarity scale calculation model;

[0028] The mass similarity scale calculation model is used to calculate the mass similarity scale λ of submarine slender flexible pipeline test components. m : λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

[0029] Preferably, in step 1, the hydraulic similarity condition calculation model further includes a momentum similarity scale calculation model;

[0030] The momentum similarity scale calculation model is used to calculate the momentum similarity scale λ of the simulation test p : λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

[0031] Preferably, in step 1, the hydraulic similarity condition calculation model also includes an energy similarity scale calculation model, wherein:

[0032] The energy similarity scale calculation model is used to calculate the energy similarity scale λ of the simulation test E : λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

[0033] Preferably, in step 1, the structural dynamic similarity condition calculation model includes a bending stiffness calculation model and a wall thickness calculation model, wherein:

[0034] The flexural stiffness calculation model is used to calculate the flexural stiffness of submarine slender flexible pipeline test components. Specifically:

[0035] Where K EI is the bending stiffness of the submarine slender flexible pipeline prototype; g is the acceleration scale; λ ρ is the density scale, λ ρ =ρ p / ρ m , ρ p represents the density of the submarine slender flexible pipeline prototype, ρ m Indicates the density of the submarine slender flexible pipeline test component; l It is a similar scale for the length of the submarine slender flexible pipeline test component;

[0036] The wall thickness calculation model is used to calculate the wall thickness of the submarine slender strip flexible pipeline test component under similar bending stiffness to the submarine slender strip flexible pipeline prototype. Specifically:

[0037]

[0038] Where K EI E is the bending stiffness of the submarine slender flexible pipeline prototype; m is the material elastic modulus of the submarine slender strip flexible pipeline test component; D is the outer diameter of the submarine slender strip flexible pipeline test component; π is the similarity coefficient of the bending stiffness of the submarine slender strip flexible pipeline test component; EI is the cross-sectional bending stiffness of the submarine slender strip flexible pipeline prototype; ρs is the material density of the submarine slender strip flexible pipeline test component; g is the acceleration of gravity, and D is the diameter of the submarine slender strip flexible pipeline test component.

[0039] Preferably, the bending stiffness of the submarine slender strip flexible pipeline prototype is calculated by the following formula:

[0040]

[0041] Where: K i is the bending stiffness of the i-th armor layer, K c is the bending stiffness of the inner conductor, α i is the helix angle between the tangent direction of the i-th layer of armor and the axial direction of the submarine slender strip flexible pipeline prototype; GJ is the torsional stiffness of the armor section, E is the elastic modulus of the armor layer; I is the moment of inertia of the copper wire section of the armor layer.

[0042] Based on the above technical objectives, the present invention has the following advantages over the prior art:

[0043] 1. The present invention constructs a hydraulic similarity condition calculation model and a structural dynamic similarity condition calculation model based on the hydraulic similarity and structural dynamic similarity between the simulation test and the prototype, so as to calculate the hydraulic similarity conditions and the structural dynamic similarity conditions accordingly, thereby effectively ensuring sufficient similarity between the simulation test and the prototype, and then more accurately obtaining prototype data that can reflect the motion law of the prototype.

[0044] 2. In the hydraulic similarity condition calculation model described in the present invention, the time similarity scale, velocity similarity scale, acceleration similarity scale, mass similarity scale, momentum similarity scale, and energy similarity scale that need to be calculated are all obtained by constructing a relationship model of the length similarity scale relative to the submarine slender strip flexible pipeline test component. The length similarity scale relative to the submarine slender strip flexible pipeline test component is determined based on the current situation of the simulation test. Therefore, the present invention seeks a relatively simple way to construct a corresponding calculation model to calculate the corresponding hydraulic similarity conditions, which is simple and feasible. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise specified, the relative arrangement of components and steps, expressions and numerical values ​​described in these embodiments do not limit the scope of the present invention. Technologies, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods and equipment should be considered part of the specification. In all examples shown and discussed here, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values.

[0046] The method for designing a submarine slender strip-shaped flexible pipeline component by simulation and scale measurement according to the present invention comprises the following steps:

[0047] Step 1: Based on the hydraulic similarity and structural similarity criteria, a hydraulic similarity condition calculation model and a structural dynamic similarity condition calculation model for the simulation test of the submarine slender strip flexible pipeline test component are constructed, wherein:

[0048] A hydraulic similarity condition calculation model is used to calculate hydraulic similarity conditions, including length similarity scale, time similarity scale, velocity similarity scale, acceleration similarity scale, mass similarity scale, momentum similarity scale, and energy similarity scale;

[0049] The structural dynamic similarity condition calculation model is used to calculate the structural dynamic similarity conditions, including the bending stiffness of the submarine slender strip flexible pipeline test component and the wall thickness of the submarine slender strip flexible pipeline test component under the bending stiffness similar to that of the submarine slender strip flexible pipeline prototype.

[0050] Specifically, in the hydraulic similarity condition calculation model of the present invention, the length similarity scale calculation model is constructed to calculate the length similarity scale λ of the submarine slender strip flexible pipeline test component. l , by building a time similarity scale calculation model to calculate the time similarity scale λ of the simulation experiment t , by building a speed similarity scale calculation model to calculate the speed similarity scale λ of the simulation test v , by building an acceleration similarity scale calculation model to calculate the acceleration similarity scale λ of the simulation test a By building a mass similarity scale calculation model, the mass similarity scale λ of the submarine slender strip flexible pipeline test component is calculated. m, by building a momentum similarity scale calculation model to calculate the momentum similarity scale λ of the simulation test p , by building an energy similarity scale calculation model to calculate the energy similarity scale λ of the simulation experiment E .

[0051] Among them: The length similarity ratio calculation model is specifically as follows:

[0052] λ l =L p / L m ;

[0053] Where, L p L is the length of the submarine slender flexible pipeline prototype. m The length dimension of the submarine slender strip flexible pipeline test component is determined based on the actual working conditions of the simulation test, thereby obtaining the length similarity ratio λ. l .

[0054] The time similarity scale calculation model, velocity similarity scale calculation model, acceleration similarity scale calculation model, mass similarity scale calculation model, momentum similarity scale calculation model and energy similarity scale calculation model are all constructed by constructing the corresponding experimental parameter scale relative to the length similarity scale λ. l The experimental parameter scale is obtained by the relationship model with respect to the length similarity scale λ l The relational model can be expressed as: λ∝λ l , where λ represents any one of the experimental parameter scales: time similarity scale, velocity similarity scale, acceleration similarity scale, mass similarity scale, momentum similarity scale, and energy similarity scale.

[0055] Through fitting or experience accumulation, in the present invention, the temporal similarity scale calculation model can be expressed as: The velocity similarity scale calculation model can be expressed as: The acceleration similarity scale calculation model can be expressed as: The mass similarity scale calculation model can be expressed as: The momentum similarity scale calculation model can be expressed as: The energy similarity scale calculation model can be expressed as:

[0056] In the present invention, the structural dynamic similarity condition calculation model includes a bending stiffness calculation model and a wall thickness calculation model, wherein:

[0057] The flexural stiffness calculation model is used to calculate the flexural stiffness of submarine slender flexible pipeline test components. Specifically:

[0058] Where K EI is the bending stiffness of the submarine slender flexible pipeline prototype; g is the acceleration scale; λ ρ is the density scale, λ ρ =ρ p / ρ m , ρ p represents the density of the submarine slender flexible pipeline prototype, ρ m Indicates the density of the submarine slender flexible pipeline test component; l The length scale is similar to that of the submarine slender flexible pipeline test component.

[0059] The bending stiffness of the submarine slender flexible pipeline prototype is calculated by the following formula:

[0060]

[0061] Where: K i is the bending stiffness of the i-th armor layer, K c is the bending stiffness of the inner conductor, α i is the helix angle between the tangent direction of the i-th layer of armor and the axial direction of the submarine slender strip flexible pipeline prototype; GJ is the torsional stiffness of the armor section, E is the elastic modulus of the armor layer; I is the moment of inertia of the copper wire section of the armor layer.

[0062] The wall thickness calculation model is used to calculate the wall thickness of the submarine slender strip flexible pipeline test component under similar bending stiffness to the submarine slender strip flexible pipeline prototype. Specifically:

[0063]

[0064] Where K EI E is the bending stiffness of the submarine slender flexible pipeline prototype; m is the material elastic modulus of the submarine slender strip flexible pipeline test component; D is the outer diameter of the submarine slender strip flexible pipeline test component; π is the similarity coefficient of the bending stiffness of the submarine slender strip flexible pipeline test component; EI is the cross-sectional bending stiffness of the submarine slender strip flexible pipeline prototype; ρ s is the material density of the submarine slender strip flexible pipeline test component; g is the acceleration of gravity, and D is the diameter of the submarine slender strip flexible pipeline test component.

[0065] Step 2: Based on the current status of simulation tests of submarine slender flexible pipeline test components, determine the length similarity scale used in the simulation test, and calculate the various test parameters of the simulation test according to the hydraulic similarity condition calculation model and the structural dynamic similarity condition calculation model constructed in Step 1;

[0066] Step 3: Based on the test parameters calculated in step 2, a submarine elongated flexible pipeline test component is manufactured, and it is ensured that the manufactured submarine elongated flexible pipeline test component meets the above-mentioned hydraulic similarity conditions and structural similarity conditions when conducting the simulation test;

[0067] Step 4: Load the fabricated submarine elongated flexible pipeline test component into a simulation test device, and install corresponding monitoring instruments or equipment on the submarine elongated flexible pipeline test component according to the test requirements. Clamp and fix the submarine elongated flexible pipeline test component using a test component fixing device, apply a force to the clamped submarine elongated flexible pipeline test component, and measure the strain data of the submarine elongated flexible pipeline test component using a strain gauge installed on the submarine elongated flexible pipeline test component, thereby monitoring the deformation of the submarine elongated flexible pipeline test component under a specific force.

[0068] Step 5: Conduct a simulation test of the submarine slender strip flexible pipeline test component according to the test conditions, and save the data monitored by the monitoring instrument or equipment into a database file;

[0069] Step 6: According to the test requirements, statistically analyze the corresponding monitoring database files and analyze the motion law data of the flexible slender strip pipeline component model reflected by the monitoring data;

[0070] Step 7: Based on hydraulic and structural similarity conditions, the motion data of the submarine elongated flexible pipeline test component obtained in Step 6 is reversely converted into motion data of the submarine elongated flexible pipeline prototype. At this point, the data obtained from the flexible elongated flexible pipeline component model test becomes prototype data that reflects the prototype's motion patterns.

Claims

1. A simulation scale design method for submarine slender strip flexible pipeline components, characterized in that: The steps include: Step 1: Based on the hydraulic similarity and structural similarity criteria, a hydraulic similarity condition calculation model and a structural dynamic similarity condition calculation model for the simulation test of the submarine slender strip flexible pipeline test component are constructed, wherein: A hydraulic similarity condition calculation model is used to calculate hydraulic similarity conditions, including length similarity scale, time similarity scale, velocity similarity scale, acceleration similarity scale, mass similarity scale, momentum similarity scale, and energy similarity scale; The structural dynamic similarity condition calculation model is used to calculate the structural dynamic similarity conditions, including the bending stiffness of the submarine slender strip flexible pipeline test component and the wall thickness of the submarine slender strip flexible pipeline test component under the bending stiffness similar to that of the submarine slender strip flexible pipeline prototype; Step 2: Based on the current status of simulation tests of submarine slender flexible pipeline test components, determine the length similarity scale used in the simulation test, and calculate the various test parameters of the simulation test according to the hydraulic similarity condition calculation model and the structural dynamic similarity condition calculation model constructed in Step 1; Step 3: Based on the test parameters calculated in step 2, a submarine elongated flexible pipeline test component is manufactured, and it is ensured that the manufactured submarine elongated flexible pipeline test component meets the above-mentioned hydraulic similarity conditions and structural similarity conditions when conducting the simulation test; Step 4: Load the manufactured submarine slender strip flexible pipeline test component into the simulation test equipment, and install corresponding monitoring instruments or equipment on the submarine slender strip flexible pipeline test component according to the test requirements; Step 5: Conduct a simulation test of the submarine slender strip flexible pipeline test component according to the test conditions, and save the data monitored by the monitoring instrument or equipment into a database file; Step 6: According to the test requirements, statistically analyze the corresponding monitoring database files and analyze the motion law data of the flexible slender strip pipeline component model reflected by the monitoring data; Step 7: Based on hydraulic similarity conditions and structural similarity conditions, the motion law data of the submarine slender strip flexible pipeline test component obtained in step 6 is reversely converted into the motion law data of the submarine slender strip flexible pipeline prototype.

2. The method for designing a submarine slender strip flexible pipeline component in a simulated scale according to claim 1, characterized in that: In step 1, the hydraulic similarity condition calculation model includes a length similarity scale calculation model; The length similarity scale calculation model is used to calculate the length similarity scale of submarine slender flexible pipeline test components. Specifically: l l =L p / L m ; Where, L p L is the length of the submarine slender flexible pipeline prototype. m It is the length dimension of the submarine slender strip flexible pipeline test component.

3. The method for designing a submarine slender strip flexible pipeline component in a simulated scale according to claim 2, characterized in that: In step 1, the hydraulic similarity condition calculation model also includes a time similarity scale calculation model; The temporal similarity scale calculation model is used to calculate the temporal similarity scale λ of the simulation test t , λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

4. The method for designing a submarine slender strip flexible pipeline component in a simulated scale according to claim 2, characterized in that: In step 1, the hydraulic similarity condition calculation model also includes a velocity similarity scale calculation model; The speed similarity scale calculation model is used to calculate the speed similarity scale λ of the simulation test v , λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

5. The method for designing a submarine slender strip flexible pipeline component in a simulated scale according to claim 2, characterized in that: In step 1, the hydraulic similarity condition calculation model also includes an acceleration similarity scale calculation model; The acceleration similarity scale calculation model is used to calculate the acceleration similarity scale λ of the simulation test a , λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

6. The method for designing a submarine slender strip flexible pipeline component in a simulated scale according to claim 2, characterized in that: In step 1, the hydraulic similarity condition calculation model also includes a mass similarity scale calculation model; The mass similarity scale calculation model is used to calculate the mass similarity scale λ of submarine slender flexible pipeline test components. m : λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

7. The method for designing a submarine slender strip flexible pipeline component in a simulated scale according to claim 2, characterized in that: In step 1, the hydraulic similarity condition calculation model also includes a momentum similarity scale calculation model; The momentum similarity scale calculation model is used to calculate the momentum similarity scale λ of the simulation test p : λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

8. The method for designing a submarine slender strip flexible pipeline component in a simulated scale according to claim 2, characterized in that: In step 1, the hydraulic similarity condition calculation model also includes an energy similarity scale calculation model, where: The energy similarity scale calculation model is used to calculate the energy similarity scale λ of the simulation test E : λ l A similar scale showing the length of the submarine slender flexible pipeline test component.

9. The method for designing a submarine slender strip flexible pipeline component in a simulated scale according to claim 1, characterized in that: In step 1, the structural dynamic similarity condition calculation model includes a bending stiffness calculation model and a wall thickness calculation model, wherein the bending stiffness calculation model is used to calculate the bending stiffness of the submarine slender strip flexible pipeline test component, specifically: Where K EI is the bending stiffness of the submarine slender flexible pipeline prototype; g is the acceleration scale; λ ρ is the density scale, λ ρ =ρ p / ρ m , ρ p represents the density of the submarine slender flexible pipeline prototype, ρ m Indicates the density of the submarine slender flexible pipeline test component; l It is a similar scale for the length of the submarine slender flexible pipeline test component; The wall thickness calculation model is used to calculate the wall thickness of the submarine slender strip flexible pipeline test component under similar bending stiffness to the submarine slender strip flexible pipeline prototype. Specifically: Where K EI E is the bending stiffness of the submarine slender flexible pipeline prototype; m is the material elastic modulus of the submarine slender strip flexible pipeline test component; D is the outer diameter of the submarine slender strip flexible pipeline test component; π is the similarity coefficient of the bending stiffness of the submarine slender strip flexible pipeline test component; EI is the cross-sectional bending stiffness of the submarine slender strip flexible pipeline prototype; ρ s is the material density of the submarine slender strip flexible pipeline test component; g is the acceleration of gravity, and D is the diameter of the submarine slender strip flexible pipeline test component.

10. The method for designing a submarine slender strip flexible pipeline component in a simulated scale according to claim 9, characterized in that: The bending stiffness of the submarine slender flexible pipeline prototype is calculated by the following formula: Where: K i is the bending stiffness of the i-th armor layer, K c is the bending stiffness of the inner conductor, α i is the helix angle between the tangent direction of the i-th layer of armor and the axial direction of the submarine slender strip flexible pipeline prototype; GJ is the torsional stiffness of the armor section, E is the elastic modulus of the armor layer; I is the moment of inertia of the copper wire section of the armor layer.

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