A method for designing a piping layout in an extended field

Abstract

The application relates to a pipeline layout design method in an extended domain, and belongs to the field of aerospace vehicle pipeline layout design. The method of the application expands the layout space of a pipeline, then carries out pipeline layout design in the extended domain, and obtains the inherent frequency of the pipeline of different design schemes. The method of the application realizes the pipeline layout design considering weight and vibration when the space is limited. Blindness and experience are avoided, and the method provides a reference for the dynamic positive design of the pipeline structure of an aircraft.

Description

Technical Field

[0001] This invention belongs to the field of aerospace vehicle piping layout design, and specifically relates to a piping layout design method in an extended domain. Background Technology

[0002] Piping systems in aerospace vehicles (including hydraulic, fuel, and air piping systems) serve as channels for the transmission of media and energy. The layout design of these systems must be carried out within limited space, while simultaneously considering requirements such as functionality, obstacle avoidance, structural strength, maintenance spacing, and vibration. Therefore, design manuals or standards stipulate general principles for piping layout design.

[0003] In practical engineering, aerospace piping design often encounters a situation where adhering to manuals / standards regarding pipe diameters and straight sections requires a large feasible layout domain. However, the space available for aircraft piping systems is sometimes very narrow, and obstacles can prevent the required feasible layout domain from being met. Currently, piping layout design in such situations relies heavily on the designer's experience, leading to significant uncertainty and frequent problems such as repeated trial and error or unreasonable dynamic performance. In such cases, it is necessary to expand the piping layout space and then design the piping layout within the expanded domain. Piping layout design within the expanded domain must consider factors such as weight and vibration. Summary of the Invention

[0004] Technical problems to be solved

[0005] To address the issue of insufficient layout space in aircraft structures, this invention proposes a piping layout design method within an extended domain. It introduces the concept of an extended domain and implements a piping layout design method that considers weight and vibration within this domain. This provides a reference for the forward dynamic design of aircraft piping structures.

[0006] Technical solution

[0007] First, it is necessary to determine whether the actual three-dimensional dimensions of the space meet the requirements of the feasible domain size for normal pipeline layout. The determination method is as follows: based on the coordinates (x, y) of the two interfaces, inlet A0 and outlet B0 of the actual pipeline. A0 ,y A0 ,z A0 ) and (x B0 ,y B0 ,z B0 ), calculate the actual three-dimensional dimensions of the space (i.e., the feasible region of the original layout).

[0008] Straight segments (L) in the direction of pipe entry and exit through the pipe port. s ) and bending radius (R) bTwo design parameters are used to determine whether the actual space size is greater than the size required by the feasible layout domain. If the size is greater, the layout design is implemented according to the original feasible layout domain.

[0009] If the three-dimensional coordinates of the inlet A0 and outlet B0 of the actual pipeline have a dimension (L) less than or equal to the dimension required in the normal layout direction in any one of the three directions (x, y, z). s +R b That is, when one of the following situations occurs, i.e.

[0010] |x B0 -x A0 |≤L s +R b , or |y B0 -y A0 |≤L s +R b , or |z B0 -z A0 |≤L s +R b

[0011] When the coordinates in a certain direction satisfy the above formula, it is said that the original layout feasible domain size in that corresponding direction is insufficient, and the pipeline layout design within the normal layout feasible domain cannot be implemented.

[0012] According to the concept of extended domain proposed in this invention, the original normal layout domain is extended in a certain insufficient direction (here it is assumed that the layout size is insufficient in the y-direction). The extension method is to start from the interface and extend along the insufficient direction (y-direction) until the minimum layout surface is reached. The method for determining the minimum layout surface is as follows:

[0013] (|y A2 -y A0 |>L s +R b1 )∩(|y B0 -y A2 |>R b2 +R b3 )

[0014] In the formula, the symbol “∩” represents the relationship of an AND gate, meaning that both conditions must be met simultaneously to satisfy the layout extension domain condition.

[0015] After the above expansion method, a new cuboid expansion layout domain is obtained. The pipe layout method in the expansion domain is as follows: determine two bending points in the minimum layout plane, and the bending angle of the two broken line segments is ≥90°. The entire pipe shape can be determined. The bending points of this pipe shape are all in the minimum layout plane, so it is the pipe shape with the lowest quality and meets the requirements of the manual / specification.

[0016] After obtaining the preliminary pipe shape, further optimization design can be implemented. The optimization goal is to ensure that the natural frequency of the pipe avoids potential excitation frequencies. The optimization design method is as follows: for planar pipe shapes, the natural frequency of the pipe can be modified by adjusting the length of the straight segments in the extension direction; for spatial pipes, the natural frequency of the pipe can be modified by adjusting the coordinate values ​​of the two bend points C1 and C2; and to ensure the design requirement that the angle of each bend segment is ≥90°, the lengths of the two broken line segments C1C2 and B2C2 should both be greater than twice the bending radius of the pipe, i.e.

[0017] (C1C2>2R b )∩(B2C2>2R b )

[0018] This enables the dynamic optimization design of pipeline layout within the extended domain.

[0019] Beneficial effects

[0020] This invention addresses the problem that the space required for the original feasible layout cannot be met due to factors such as narrow laying space and obstacles in aircraft piping systems. It proposes the concept of a layout extension domain and a method for determining the minimum layout surface, expanding the piping layout space. Piping layout design is then performed within this extension domain, and the natural frequencies of different design schemes are obtained. This invention realizes a method for piping layout design that considers weight and vibration under space constraints. It avoids blind and empirical approaches and provides a reference for the dynamic forward design of aircraft piping structures. Attached Figure Description

[0021] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0022] Figure 1 The length occupied by straight sections and bending radii should be considered in the direction of pipeline inlet and outlet.

[0023] Figure 2 Expansion of the pipeline layout area (plan view);

[0024] Figure 3 A schematic diagram of the layout domain extending along the direction of entry A0 (x direction);

[0025] Figure 4 A schematic diagram of the pipeline layout design within the extended domain;

[0026] Figure 5 Three layout schemes for pipelines in the extended domain within three-dimensional space;

[0027] Figure 6 Case study of planar piping expansion area layout;

[0028] Figure 7 Planar tubular shape obtained using the extended domain layout method;

[0029] Figure 8 Case studies on spatial piping inlets, outlets, and layout expansion areas. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0031] The installation of aircraft piping systems (including hydraulic and engine piping systems) is generally completed on the basis of existing structures. The piping layout is designed based on the locations of the two interfaces to be connected and the available space. However, the space available for piping installation in aircraft is relatively small. To meet the requirements for straight sections and bending radii at entrances and exits, a large layout space (called the feasible layout region) is needed. If the feasible layout region cannot meet the requirements, the layout region needs to be expanded. This expansion of the feasible layout region is called the extended region. This invention proposes the concept of the extended region, a method for determining the minimum layout surface, and a method for designing the piping layout within the extended region.

[0032] (1) The concept of extended domain

[0033] Aerospace piping design standards stipulate that piping should have a sufficient straight section from the end along the exit direction (medium transmission direction). The length of the straight section varies depending on the industry's design standards (some standards specify L). s =2D0, where D0 is the outer diameter of the pipe (some standards specify 16mm or other dimensions). Furthermore, the bending radius R when the pipe is bent... b There are also relevant regulations; generally speaking, R b The outer diameter of the pipe is taken as 4 times. Therefore, the length occupied by the straight section and the bending radius should be considered in the direction of the pipe interface exit, such as... Figure 1 As shown. Figure 1 For the planar conduit shown, the straight segments L of the conduit at its inlet A0 and outlet B0 should be deducted from their respective outgoing directions. s Then, the layout design is carried out within the range of A1B1. At this time, the area between A1B1 is called the layout feasible region.

[0034] according to Figure 1 The required straight section length for the pipeline interface outlet section, and the remaining section L after deducting the straight section at inlet A0 and outlet B0.rA and L rB When laying curved pipes, the remaining section L rA and L rB The bending radius R should be satisfied. b The requirements. That is...

[0035] L rA ≥R b ∩L rB ≥R b (1)

[0036] In the formula, the symbol “∩” represents the relationship of an AND gate, meaning that both conditions must be met simultaneously to satisfy the feasible region condition of the layout.

[0037] Reference Figure 1 The length requirement for the pipeline outlet section at the interface: The length of the pipeline along the outlet directions of interfaces A0 and B0 should meet the straight section L requirement. s and bending radius R b Therefore, the lengths of the straight segments A0A2 and B0B2 leading out from the interface should meet the following requirements:

[0038]

[0039] It should be noted that if the length along the direction of a certain interface A0 and B0 of the pipeline is insufficient, that is, if equation (2) is not satisfied, the layout needs to be extended in the direction of the pipeline interface.

[0040] To illustrate this point, such as Figure 2 In the planar pipeline scenario shown, the inlet A0 is along the y-direction and the outlet B0 is along the x-direction. However, due to structural space limitations (such as obstacles, pipe joint locations, etc.), the length of the joint A0 in the inlet direction is insufficient. If it is directly bent, the straight segment length in the inlet direction will be insufficient, i.e., equation (2) is not satisfied. If described using coordinates, it would be...

[0041] |y B0 -y A0 |≤L s +R b (3)

[0042] In this situation, the original feasible domain space is insufficient. Therefore, it is necessary to expand the layout domain in the direction of pipeline exit (y direction).

[0043] (2) Method for determining the extended domain

[0044] for Figure 2 In the planar scenario shown, the length of interface A0 in the inlet direction is insufficient. Therefore, it is necessary to extend from A0 to A2 along the inlet direction (e.g., Figure 2As shown in the diagram, the surface perpendicular to the lead-out direction and passing through point A2 is called the minimum layout surface, which is the minimum boundary of the extended domain. The minimum extended surface needs to be determined by comprehensively comparing the following formulas.

[0045] (|y A2 -y A0 |>L s +R b1 )∩(|y B0 -y A2 |>R b2 +R b3 (4)

[0046] In the formula, the symbol “∩” represents the relationship of an AND gate, meaning that both conditions must be met simultaneously to satisfy the layout extension domain condition.

[0047] For three-dimensional spatial pipelines, such as Figure 3 In the example shown, the exit direction of entrance A0 is the x-direction, and the coordinates are (x... A0 ,y A0 ,z A0 The exit direction of B0 is the y-direction, and its coordinate is (x...). B0 ,y B0 ,z B0 The length of interface A0 in the inlet direction is insufficient; therefore, it needs to be extended from A0 along the x-direction to A2 (e.g., ...). Figure 3 As shown in the figure, the surface perpendicular to the x-axis and passing through point A2 is called the minimum layout surface A2DEF, which is the minimum boundary of the extended domain.

[0048] At the same time, the bending radius design requirements of the pipeline layout are taken into account. Figure 3 In the case shown, the method for determining the location of the minimum spatial expansion surface is as follows:

[0049] (|x A2 -x A0 |>L s +R b1 )∩(|x B0 -x A2 |>2R b (5)

[0050] (3) Tubular layout design method in the extended domain

[0051] After the above expansion method, the lengths of A0 and A2 are guaranteed to still satisfy equation (2). This results in a new cuboid expansion layout domain, assuming its length, width, and height are l1, l2, and l3, respectively. The pipeline will be designed with bending within this cuboid expansion domain, such as... Figure 4 As shown.

[0052] As can be seen, this pipeline layout method within the extended domain essentially determines the entire pipe shape by defining two bend points C1 and C2 within the minimum layout plane. This is based on design requirements such as the extreme positions of the minimum layout plane, weight, bending radius, and bending angle ≥90°. For example, due to the bending radius requirement of the bend segment, the lengths of the two broken line segments C1C2 and B2C2 should be greater than twice the pipeline bending radius.

[0053] (C1C2>2R b )∩(B2C2>2R b (6)

[0054] Because the aircraft has weight control requirements, if the first bend point C1 is taken as point A2, the layout design can be carried out on the minimum layout plane. Furthermore, the three bends are relatively short in length and have low mass. Therefore, this invention provides three layout design schemes within the pipeline expansion domain under this condition, such as... Figure 5 As shown.

[0055] The following examples demonstrate the pipeline layout design method for the extended domain proposed in this invention, using both planar and spatial scenarios as specific embodiments.

[0056] Example 1: Plane Case

[0057] First, let's consider the planar case (assuming the XOY plane), such as... Figure 6 As shown, if a pipeline needs to be designed between inlet A0 and outlet B0, where the coordinates of inlet A0 are (0, 0) and the inlet direction is in the negative y-axis direction, and the coordinates of outlet B0 are (180, 40) and the outlet direction is in the positive x-axis direction, with the coordinate units being mm, the outer diameter D of the pipeline to be designed between the two interfaces needs to be 12 mm, and the bending radius R... b1 The straight section L is 4 times the pipe diameter, or 48mm. s The required length is 16mm. Bending radius R b2 =40mm, R b3 =40mm.

[0058] In this model, the length of connector B0 in the introduction direction is sufficient, but the distance between connector A0 in the introduction direction and connector B0 is insufficient, i.e.

[0059] |x B0 -x A0 |=180mm>(L s +R b =64mm)

[0060] |y B0 -y A0 |=40mm<(L s +R b =64mm)

[0061] Therefore, according to equation (4), it expands to the minimum layout surface in the negative y direction.

[0062] (|y A2 |>64)∩(|y A2 |>120)

[0063] That is, the absolute value of the y-coordinate of the minimum layout plane should be greater than 120mm. In this example, 136mm is selected. Based on the requirements of the straight segments of the two interfaces, the resulting tube shape on this extended minimum layout plane is as follows. Figure 7 As shown.

[0064] Figure 7 The pipe shape shown can be further designed according to the dynamic design requirements of the pipeline, for example, by adjusting... Figure 7 The length of the straight section at the inlet and outlet can change the dynamic characteristics of the pipeline structure. Table 1 lists the first three natural frequencies of the pipeline for different straight section lengths.

[0065] Table 1. Planar pipe structure and first three natural frequencies within the extended domain.

[0066]

[0067]

[0068] Example 2: Spatial Case Study

[0069] like Figure 8 In the spatial configuration shown, if a pipeline needs to be designed between inlet A0 and outlet B0, the one-stage bend, two-stage bend, and three-stage bend schemes proposed in this invention can be used for design. Here, it is assumed that the coordinates of inlet A0 are (0, 0, 0) and the coordinates of outlet B0 are (50, 200, 150), with the coordinate unit being mm. The pipeline diameter D to be designed within the two joints is 12 mm, and all bending radii R... b All are 4 times the pipe diameter, i.e., 48mm, with straight section L. s The length requirement is 16mm.

[0070] According to the method proposed by the present invention, the minimum layout surface of the extended domain is first determined according to equation (5), such as Figure 8 As shown, the minimum layout plane is a plane passing through point A2 and perpendicular to the entrance / exit direction. This plane should satisfy...

[0071] |x A2 -x A0 |>(L s +R b =64mm)

[0072] |x B0 -x A2 |>(2R b=96mm)

[0073] Based on the actual coordinates, Figure 8 In the minimum layout shown, the x-coordinate of point A2 should be greater than 146mm. In this example, the x-coordinate of the extended surface is selected as 150mm. A three-section bend pipe layout design is implemented within this extended area, using... Figure 5 The tubular layout method yields the tubular structure form and the corresponding first three natural frequencies, as shown in Table 2.

[0074] Table 2. Pipeline layout forms and corresponding natural frequencies in the extended domain under three-dimensional conditions.

[0075]

[0076]

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A method for designing pipeline layout within an extended domain, characterized in that... The steps are as follows: First, it is necessary to determine whether the actual three-dimensional dimensions of the space meet the requirements of the feasible domain size for normal pipeline layout; the judgment method is: based on the coordinates (x, y) of the two interfaces of the actual pipeline inlet A0 and outlet B0. A0 ,y A0 ,z A0 ) and (x B0 ,y B0 ,z B0 The actual three-dimensional dimensions of the space are the feasible region of the original layout. Straight segments (L) in the direction of pipe entry and exit through the pipe port. s ) and bending radius (R) b Two design parameters are used to determine whether the actual space size is greater than the size required by the feasible layout domain. If the size is greater, the layout design is implemented according to the original feasible layout domain. If the three-dimensional coordinates of the inlet A0 and outlet B0 of the actual pipeline have a dimension (L) less than or equal to the dimension required in the normal layout direction in any direction. s +R b That is, when one of the following situations occurs, i.e. |x B0 -x A0 |≤L s +R b , or |y B0 -y A0 |≤L s +R b , or |z B0 -z A0 |≤L s +R b When the coordinates in a certain direction satisfy the above formula, it is said that the original layout feasible region size in that corresponding direction is insufficient and the pipeline layout design within the normal layout feasible region cannot be implemented. According to the concept of extended domain proposed in this invention, the original normal layout domain is extended in a certain insufficient direction. The extension method starts from the interface and extends along the insufficient direction until the minimum layout surface is reached. The method for determining the minimum layout surface is as follows: (|y A2 -y A0 |>L s +R b1 )∩(|y B0 -y A2 |>R b2 +R b3 ) In the formula, the symbol "∩" represents the "AND gate" relationship, meaning that both conditions must be met simultaneously to satisfy the layout extension domain condition; After the above expansion method, a new cuboid expansion layout domain is obtained. The pipe layout method in the expansion domain is as follows: determine two bending points in the minimum layout plane, and the bending angle of the two broken line segments is ≥90°. The entire pipe shape can be determined. The bending points of this pipe shape are all in the minimum layout plane, so it is the pipe shape with the lowest quality and meets the requirements of the manual / specification. After obtaining the initial pipe shape, further optimization design can be carried out. The optimization goal is to ensure that the natural frequency of the pipeline avoids possible excitation frequencies, thereby realizing the dynamic optimization design of the pipeline layout in the extended domain.

2. The pipeline layout design method in an extended domain according to claim 1, characterized in that... The optimization design method is as follows: For planar pipes, the natural frequency of the pipe can be modified by adjusting the length of the straight segments in the extension direction; for spatial pipes, the natural frequency can be modified by adjusting the coordinate values ​​of the two bend points C1 and C2; and to ensure the design requirement that the angle of each bend segment is ≥90°, the lengths of the two broken line segments C1C2 and B2C2 should both be greater than twice the pipe bending radius, i.e. (C1C2>2R b )∩(B2C2>2R b )。 3. A computer system, characterized in that... include: One or more processors, a computer-readable storage medium for storing one or more programs, wherein, when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the method of claim 1.

4. A computer-readable storage medium, characterized in that... The device stores computer-executable instructions, which, when executed, are used to implement the method of claim 1.

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