Air device model profile optimization method, device, equipment and storage medium

Abstract

The application provides a profile optimization method, device and equipment of a pneumatic device model and a storage medium, and belongs to the field of structure optimization. The method comprises the following steps: performing mesh division on a model of an original pneumatic device to obtain a mesh file; selecting a region needing deformation in the mesh file and obtaining an original curve function; determining a group of deformation parameters, configuring a plurality of groups of offset operators and transition operators for the group of deformation parameters, multiplying each group of offset operators and transition operators, and then adding the result to the original curve function to obtain different curve functions after deformation, so that the mesh of the region needing deformation is deformed to generate a plurality of mesh files with different curve styles; performing flow field numerical simulation on different mesh files to obtain flow parameters of each mesh file, comparing the flow parameters of each mesh file, and selecting a profile with the best performance according to the comparison result. The application is based on node offset technology, and the mesh of a certain region is deformed, so that the profile is deformed.

Description

Technical Field

[0001] This invention belongs to the field of structural optimization technology, specifically relating to a method, apparatus, equipment, and storage medium for optimizing the profile of a pneumatic device model. Background Technology

[0002] The profile of a pneumatic device has a significant impact on the flow of gas. For example, the inner profile of a rocket engine nozzle affects its operating efficiency. A good profile can reduce gas flow resistance and prevent flow separation. When the designed profile fails to produce satisfactory results in numerical simulations, it needs to be modified.

[0003] Traditional optimization methods often involve modifications to geometry and topology (e.g., changing straight surfaces to curved surfaces), typically requiring remodeling and meshing of the model. In particular, for complex surface optimization problems, multiple model adjustments and optimizations may be necessary to achieve satisfactory results, consuming significant time and effort. Summary of the Invention

[0004] To address the problem that modifying the surface curve of existing pneumatic devices requires remodeling and meshing the model, which consumes a lot of time and effort, this invention provides a method, apparatus, device, and storage medium for surface optimization of pneumatic device models.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for optimizing the profile of a pneumatic device model includes the following steps:

[0007] The original pneumatic device model is meshed to obtain the mesh file of the original pneumatic device;

[0008] Select the region to be deformed from the original pneumatic device mesh file and obtain the original curve function of the region to be deformed; determine a set of deformation parameters containing different mesh node coordinate offsets, and configure multiple sets of offset operators and transition operators for this set of deformation parameters. Multiply each set of offset operators and transition operators and then superimpose them onto the original curve function to obtain different deformed curve functions, thereby deforming the mesh of the region to be deformed and generating multiple mesh files with different curve styles; the offset operators and transition operators are functions that make the deformed curves continuous and smooth.

[0009] Numerical simulations of the flow field were performed using different grid files under the same computational conditions to obtain the flow parameters of each grid file. The flow parameters of each grid file were then compared, and the best-performing profile was selected based on the comparison results.

[0010] Preferably, the deformed curve function is:

[0011] y(x)=y0(x)+d(x)*s(x)

[0012] Where y0(x) is the original curve function, y(x) is the transformed curve function, d(x) is the offset operator, and s(x) is the transition operator.

[0013] Preferably, the offset operator is any one of a constant function, a linear function, a quadratic function, or a spline curve function.

[0014] Preferably, the transition operator is a piecewise function composed of a normalized sin function and a constant function y(x) = 1.

[0015] Preferably, the transition operator is multiplied by the offset operator, with the ordinate interval being [0,1]. The form of the multiplication of the transition operator and the offset operator is expressed as follows:

[0016]

[0017] In the formula, x1 and x4 are the left and right endpoints of the x-coordinate interval of the deformed part of the curve, respectively, and x2 and x3 are the left and right endpoints of the x-coordinate interval of the fully deformed segment, respectively. When x < x1, s(x) remains 0, that is, the offset operator cannot provide any change, and the curve does not deform. When x1 ≤ x < x2, s1(x) gradually increases from 0 to 1, the change provided by the offset operator is limited, the curve begins to deform, and gradually transitions from the original curve to the deformed curve, which is called the transition segment. When x2 ≤ x ≤ x3, s(x) equals 1, the offset operator provides all the change, and this segment is called the fully deformed segment. When x3 < x ≤ x4, s2(x) gradually decreases from 1 to 0, the change provided by the offset operator is limited, and the curve gradually transitions from the deformed curve to the original curve again. When x > x4, s(x) remains 0, the offset operator cannot provide any change, and the curve does not deform.

[0018] Preferably, before obtaining the different deformed curve functions, the abscissa of the transition operator is normalized.

[0019] The present invention also provides a pneumatic device profile optimization device, comprising:

[0020] The mesh generation module is used to generate a mesh from the original pneumatic device model to obtain the mesh file of the original pneumatic device.

[0021] The surface optimization module is used to select the region to be deformed in the original aerodynamic device mesh file and obtain the original curve function of the region to be deformed; determine a set of deformation parameters containing different mesh node coordinate offsets, and configure multiple sets of offset operators and transition operators for this set of deformation parameters. After multiplying each set of offset operators and transition operators, the results are superimposed on the original curve function to obtain different deformed curve functions, thereby deforming the mesh of the region to be deformed and generating multiple mesh files with different curve styles; the offset operators and transition operators are functions that make the deformed curves continuous and smooth.

[0022] The profile selection module is used to perform flow field numerical simulations of different mesh files under the same computational conditions, obtain the flow parameters of each mesh file, compare the flow parameters of each mesh file, and select the profile with the best performance based on the comparison results.

[0023] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes any step of the method for optimizing the profile of the pneumatic device model.

[0024] The present invention also provides a computer-readable storage medium storing a computer program, characterized in that, when the computer program is loaded by a processor, it is capable of executing any of the steps in the surface optimization method of the pneumatic device model.

[0025] The pneumatic device model profile optimization method provided by this invention has the following beneficial effects:

[0026] This invention first meshes the original aerodynamic device model to obtain a mesh file. Based on this mesh file, a non-parametric surface optimization design method based on node offset technology is proposed. This method involves obtaining the original curve function of the region to be deformed, determining a set of deformation parameters containing different mesh node coordinate offsets, and configuring multiple sets of offset and transition operators for these parameters. Each set of offset and transition operators is multiplied and superimposed onto the original curve function. By directly deforming the mesh in a specific region, the surface is deformed, thus generating a new mesh file for calculation. This invention uses this method to optimize part of the surface profile of a certain aerodynamic device. After numerical calculation and comparative analysis, a surface profile curve with better aerodynamic performance was obtained. Attached Figure Description

[0027] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A flowchart of the surface optimization method for the pneumatic device model provided by the present invention;

[0029] Figure 2 An example of curve deformation when a spline curve function is used as an offset operator;

[0030] Figure 3 Example of curve deformation when the constant function y(x) = s is used as the offset operator without transition operators;

[0031] Figure 4 Examples of curve deformation when the constant function y(x) = s is used as the offset operator under the condition of a transition operator; (a) the transition operator curve; (b) the original curve, the curve of change, and the deformed curve;

[0032] Figure 5 Examples of local node offsets at the top and bottom boundaries of a rectangular block; (a) original mesh, (b) deformed mesh;

[0033] Figure 6 A histogram of grid quality;

[0034] Figure 7 Examples of deformation of the lower boundary curve of a rectangular block: (a) Transition operator curve for the horizontal axis, (b) Transition operator curve for the vertical axis, (c) Original curve, curve of change, and curve after deformation;

[0035] Figure 8 This refers to a portion of the pneumatic device area.

[0036] Figure 9 Examples of surface curve deformation: (a) Abscissa transition operator curve, (b) original surface curve, change curve and deformed curve;

[0037] Figure 10 Examples of node offsets; (a) original mesh, (b) deformed mesh (y = 160);

[0038] Figure 11 Mach number cloud plot; (a) original model, (b) deformed model (y = 160);

[0039] Figure 12 Here are the streamline diagrams; (a) the original model, and (b) the deformed model (y = 160).

[0040] Figure 13Mach number contour plots (0-8Ma) corresponding to the ordinates of different control points; (a)y=60, (b)y=80, (c)y=100, (d)y=120, (e)y=140, (f)y=160, (g)y=180, (h)y=200, (i)y=220, (j)y=240. Detailed Implementation

[0041] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0042] First, the principle of the node offset technology proposed in this invention will be explained.

[0043] The most important parts of node offset technology are the offset operator, transition operator, and node offset method, which will be introduced in detail below.

[0044] First, the offset operator

[0045] The function of an offset operator is to increase or decrease the ordinate of points within a selected region by a certain value, thereby changing the shape of the original curve. For example, in y(x) = y0(x) + d(x), where y0(x) is the original curve function and y(x) is the transformed curve function, then d(x) is the offset operator. The x-coordinate interval of the offset operator can be the same as that of the original curve function, or it can be included within the x-coordinate interval of the original curve function.

[0046] To transform the original curve into different shapes, different offset operators need to be selected, such as constant functions, linear functions, and quadratic functions. However, if it is necessary to ensure that the deformed curve is continuous and smooth, spline curve functions can be used. A spline is a tool used in shipbuilding and engineering drawing to draw smooth curves. Its shape is generally a slender, flexible wooden strip. After fixing its left and right ends, several nails are used as control points to change its shape, while the rest is allowed to bend freely. By drawing a line along the wooden strip, a smooth spline curve can be obtained. Spline curves have two advantages: first, they can guarantee passing through the specified points, allowing them to be constructed into various shapes; second, their first and second derivatives are continuous at every point, ensuring the continuity of the curve and a uniform change in curvature.

[0047] To better demonstrate the controllability and smoothness of spline curves, a curve with a relatively complex shape was selected. The coordinates of the left and right endpoints of the spline curve are (a2,0) and (b2,0) respectively. Three control points are used inside the curve to change its shape, with coordinates (m1,n1), (m2,n2), and (m3,n3) respectively. Figure 2 As shown, using the spline curve function mentioned above as the offset operator, the original curve's abscissa interval is [a1, b1]. The original curve is deformed within this interval, with a slight increase in the ordinate value. Furthermore, since the original curve is a straight line, the deformed curve remains smooth within this interval. Theoretically, different spline curve functions can be used to deform the original curve into various desired shapes, offering a high degree of freedom.

[0048] The example given above is somewhat special, referring to the case where the offset operator has a value of 0 at the left and right endpoints of its interval. However, if the change is not zero at the left and right endpoints of the interval, it will cause the deformed curve inside the interval to be discontinuous with the undeformed curve outside the interval at the endpoints. For example... Figure 3 As shown, taking the constant function y(x) = s as the offset operator, the x-coordinate interval of the offset operator is selected as [a2, b2], and the x-coordinate interval of the original curve is [a1, b1]. It is found that the deformed curve breaks at the two points x = a2 and x = b2. To solve this problem, a transition operator needs to be introduced to control the offset operator to a certain extent, ensuring that the deformed curve remains continuous.

[0049] Second, transition operators

[0050] The function of the transition operator is to control the change in the ordinate provided by the offset operator, thus transitioning the deformed curve to the undeformed curve. For example, in y(x) = y0(x) + d(x) * s(x), y0(x) is the original curve function, y(x) is the deformed curve function, d(x) is the offset operator, and s(x) is the transition operator. In this case, the abscissa interval of the offset operator needs to be the same as that of the original curve function, and the transition operator also acts on the entire abscissa interval of the original curve function. Since the transition operator needs to be multiplied by the offset operator, its ordinate interval is [0,1], and its form is generally as shown in equation (1).

[0051]

[0052] In the formula, x1 and x4 are the left and right endpoints of the x-coordinate interval of the deformed part of the curve, respectively, and x2 and x3 are the left and right endpoints of the x-coordinate interval of the fully deformed segment, respectively. When x < x1, s(x) remains 0, meaning the offset operator cannot provide any change, and the curve does not deform; when x1 ≤ x < x2, s1(x) gradually increases from 0 to 1, the change provided by the offset operator is somewhat limited, and the curve begins to deform, gradually transitioning from the original curve to the deformed curve, called the transition segment; when x2 ≤ x ≤ x3, s(x) equals 1, the offset operator provides all the change, and this segment is called the fully deformed segment; when x3 < x ≤ x4, s2(x) gradually decreases from 1 to 0, the change provided by the offset operator is somewhat limited, and the curve gradually transitions from the deformed curve back to the original curve; when x > x4, s(x) remains 0, the offset operator cannot provide any change, and the curve does not deform. Using this type of transition operator can ensure the continuity of the curve after deformation.

[0053] To facilitate the selection of transition operators, the x-coordinates of the transition operators need to be normalized during calculation. For example, when x1 ≤ x < x2, using X = (x - x1) / (x2 - x1) as the x-coordinate transforms s1(x) into a function with both the x-coordinate and y-coordinate intervals [0, 1]. As x gradually increases from 0 to 1, y also gradually increases to 1. There are many possible functions that satisfy this condition, such as the normalized sin function, with y = x and y = x 2 Power functions, represented by [example function name], etc.

[0054] like Figure 4 As shown, the transition operator is a piecewise function composed of the normalized sin function and the constant function y(x) = 1. The offset operator is still the constant function y(x) = s selected above. The x-coordinate interval of the original curve is [a1, b1], the x-coordinate interval of the deformed part of the curve is selected as [a2, b2], and the x-coordinate interval of the fully deformed segment is selected as [a3, b3]. Figure 3 In contrast, the deformed curve will not break at the two ends of the horizontal coordinate interval of the fully deformed segment, and the fully deformed segment curve will gradually transition to the undeformed curve.

[0055] If a smoother transition is needed between the fully deformed curve and the undeformed curve, the transition operator can be reselected or modified. For example... Figure 4As shown in (b), the x-coordinate interval of the sin function is expanded, modifying it to the form (sin(-0.5π+X*π)+1) / 2, and then combined with the constant function y(x)=1 as a transition operator. The offset operator remains the constant function y(x)=s selected above. The x-coordinate interval of the original curve is [a1,b1], the x-coordinate interval of the deformed part of the curve is selected as [a2,b2], and the x-coordinate interval of the fully deformed segment is selected as [a3,b3]. Figure 4 Compared to the deformed curve in (a), the transition between the fully deformed section and the undeformed section is smoother, without sharp turns.

[0056] Third, node offset method

[0057] The purpose of node offset is to modify a portion of the mesh within a mesh file, changing the shape of the mesh in that area, thereby deforming the original model surface. To achieve this, the original aerodynamic device model first needs to be meshed to obtain the original aerodynamic device mesh file. Then, this file is imported into the program, the area to be deformed is selected, and transition operators are used to deform the mesh in this area. Finally, the modified mesh is rewritten into a new file and exported.

[0058] Based on this, such as Figure 1 As shown, the specific steps of the pneumatic device model profile optimization method provided by the present invention include:

[0059] Step 1: Mesh the original pneumatic device model to obtain the mesh file of the original pneumatic device.

[0060] Step 2: Select the region to be deformed in the original pneumatic device mesh file and obtain the original curve function of the region to be deformed; determine a set of deformation parameters containing different mesh node coordinate offsets, and configure multiple sets of offset operators and transition operators for this set of deformation parameters. Multiply each set of offset operators and transition operators and then superimpose them onto the original curve function to obtain different deformed curve functions, so that the mesh of the region to be deformed is deformed, generating multiple mesh files with different curve styles; the offset operators and transition operators are functions that make the deformed curves continuous and smooth.

[0061] Step 3: Perform flow field numerical simulations of different grid files under the same calculation conditions to obtain the flow parameters of each grid file, compare the flow parameters of each grid file, and select the profile with the best performance based on the comparison results.

[0062] To more intuitively demonstrate the effect of node offset, a 2D structured mesh generated by ICEMCFD is used as an example. The original mesh is as follows: Figure 5As shown in (a), the flow field region is 100×100 in size. There is a 40×20 rectangular block at the center of the flow field. The distance between the rectangular block and the left and right boundaries of the flow field is 30, and the distance between the rectangular block and the upper and lower boundaries of the flow field is 40.

[0063] The goal of node offset is to make the upper and lower boundaries of the rectangular block bulge upwards based on the offset operator. Therefore, the range of operation for both the offset operator and the transition operator is 30≤x≤70, and the mesh outside this range remains unchanged. The difference between node offset and single-curve deformation is that if all meshes within this range are moved upwards, the upper and lower boundaries of the flow field will also deform; however, if only the meshes within the range of 40≤y≤60 are deformed, the deformed meshes will overlap with the original meshes, making them unsuitable for numerical simulation. Therefore, in addition to the existing horizontal axis transition operator, a new vertical axis transition operator needs to be added: its range is 0≤y≤100. When 0≤y<40, the value of the transition operator gradually increases from 0 to 1 to prevent deformation of the upper and lower boundaries of the flow field; when 40≤y≤60, the value of the transition operator remains at 1, so as not to affect the change in the upper and lower boundaries of the rectangular block; when 60<y≤100, the value of the transition operator gradually decreases from 1 to 0.

[0064] The deformed mesh is as follows Figure 5 As shown in (b), the figure shows that under the combined action of the offset operator and the horizontal axis transition operator, the upper and lower boundaries of the rectangular block are deformed. The fully deformed segment is in the range of 40≤x≤60, and the transition segment is in the range of 30≤x<40 and 60<x≤70. When observing the change in the vertical axis of the mesh within this range, it is found that the change in the mesh is the largest at the upper and lower boundaries of the rectangular block, and the change in the mesh gradually decreases as it moves away from the rectangular block. The mesh at the upper and lower boundaries of the flow field hardly changes, thus avoiding the deformation of the upper and lower boundaries of the flow field. The mesh quality histogram is shown below. Figure 6 As shown, the lowest mesh quality is 0.987, but 72.786% of the mesh quality can be maintained above 0.999. The calculated average mesh quality is 0.998, indicating that the mesh quality can still be maintained at a high value after node offset, and has little impact on numerical calculation.

[0065] The original curve, the change curve, the deformed curve, and the two types of transition operator curves of the lower boundary of the rectangular block are shown below. Figure 7 As shown in the figure, the change curve is a cubic spline curve with the coordinates of its left and right endpoints and the coordinates of its intermediate control point being (30,1), (70,1) and (50,3) respectively. Both types of transition operators use the normalized sin function.

[0066] Example 1

[0067] Figure 8The image shows a portion of a pneumatic device, with the arrow pointing to the gas outlet and the remainder representing the device wall. In this model, there is a significant angle between the gas outlet wall and the wall of the subsequent expansion section, which negatively impacts gas expansion. Therefore, the main direction of the profile optimization is to transform this portion of the profile from a straight line into a curve.

[0068] The surface optimization method for the pneumatic device model provided in this embodiment specifically includes the following steps:

[0069] Determine a different set of deformation parameters.

[0070] Without remodeling and meshing, the selected surface is deformed to generate several mesh files with different curve styles.

[0071] Numerical simulations of the flow field were performed under the same computational conditions. The flow parameters of each grid file were compared, and the best-performing profile was selected.

[0072] To ensure the smoothness of the profile curve, a cubic spline curve function is chosen as the offset operator. The abscissa at the gas outlet is x = 5350, and the abscissas of the start and end points of the rear expansion section are x = 5523.2 and x = 7064.8, respectively. Therefore, the abscissa interval of the offset operator is [5350, 7064.8], and the coordinates of the left and right endpoints are (5350, 0) and (7064.8, 0), respectively. The coordinates of the internal control point are selected as (6207.4, 60). In addition, to obtain a series of curves with different styles, nine other control points are prepared with unchanged abscissas and ordinates ranging from y = 80 to y = 240 at intervals of 20. The generated 10 offset operator curves are shown below. Figure 9 As shown in (b).

[0073] The transition operator for the horizontal coordinate is a piecewise function composed of a first-order power function y(x) = x and a constant function y(x) = 1. This function is suitable for smoothing the transition between the gas outlet wall and the subsequent expansion section wall. The transition section is the straight section at the gas outlet, with an horizontal coordinate interval of [5350, 5523.2]; the fully deformed section is the subsequent expansion section, with an horizontal coordinate interval of [5523.2, 7064.8]. The curve of the horizontal coordinate transition operator is shown below. Figure 9 As shown in (a).

[0074] The deformation results of the surface curve are as follows Figure 9As shown in (b), the solid line represents the original profile curve, the dotted line below represents the variation curve, and the dashed line above represents the deformed curve. It can be seen from the figure that the wall surface at the gas outlet and the profile of the subsequent expansion section deform, and as the ordinate value of the offset operator control point gradually increases, the variation also increases, and the upward convexity of the curve becomes increasingly obvious. At the same time, since the ordinate value of the offset operator control point is less than 240, the deformed curve will not convex too severely, preventing the internal points from being higher than the right endpoint, thus avoiding attempts to create profile curves with poor performance.

[0075] The transition operator for the vertical coordinate is also a piecewise function composed of a first-order power function y(x) = x and a constant function y(x) = 1. Since the vertical coordinate region of the entire flow field is 0 ≤ y ≤ 4000, and the vertical coordinates of the starting and ending points of the rear expansion section are y = 600 and y = 1500 respectively, the horizontal coordinate interval of the transition section is [0, 600] and [1500, 4000], and the horizontal coordinate interval of the fully deformed section is [600, 1500].

[0076] Taking the offset operator with the control point y=160 as an example, the original mesh and the deformed mesh are as follows: Figure 10 As shown in the figure, under the combined action of the offset operator and the transition operator, the wall surface at the gas outlet and the profile of the subsequent expansion section deform, and the transition is relatively smooth. The meshes on the upper and lower sides of this region are compressed or stretched to a certain extent to ensure that the upper and lower boundaries of the flow field do not deform, while the meshes on the left and right sides of the deformed region remain unchanged. In addition to this profile, the wall surface above it also deforms, which will change the flow state of the gas flow at this location. However, since it does not affect the expansion state of the gas flow, it will not be discussed, and its deformation can be prevented by adjusting the parameters.

[0077] The remaining 9 types of deformed meshes and Figure 10 (b) Since they are similar, they will not be shown again. Next, flow field numerical simulations will be performed on these 10 grid files under the same computational conditions.

[0078] Numerical calculation and result analysis

[0079] After the node offset is completed, these 10 mesh files are imported into Fluent for flow field numerical simulation. The simulation results are compared with those of the original model to observe whether the deformed surface curve has higher performance. At the same time, the 10 surface curves are compared with each other to select the most suitable surface curve.

[0080] The gas outlet boundary conditions are set as follows: pressure inlet, total pressure 6 MPa, total temperature 3000 K, outlet static pressure 50 kPa, and outlet velocity Mach 3.72.

[0081] Taking the offset operator with the control point's ordinate of y = 160 as an example, the calculated Mach number contour map is as follows: Figure 11 As shown in (b), it can be used with Figure 11 (a) is compared with the original model operating conditions. The streamline diagram is as follows: Figure 12 As shown in the figure, the gas flow continues to expand and accelerate along the rear expansion section. In the original model condition, the gas flow could not maintain its original flow state when it reached the tail of the expansion section, and flow separation occurred, with the maximum velocity reaching Mach 7.73 behind the expansion section. In the deformed model condition, although the friction with the wall caused the velocity around it to slow down, the gas flow could continue to flow along the expansion section wall until it left, with the maximum velocity reaching Mach 7.98 behind the expansion section, proving that the deformed profile curve does indeed have better performance.

[0082] Mach number contour plots corresponding to the ordinates of different control points are as follows: Figure 13 As shown in the figure, the Mach number range is 0–8 Ma. The maximum Mach number corresponding to the ordinate of different control points is shown in Table 1.

[0083] Combining the images and tables, it can be seen that when the ordinate of the control point is no greater than y = 160, the larger the ordinate of the control point, the better the flow state of the gas flow in the expansion section, and the higher the maximum Mach number that can be achieved, up to a maximum of Mach 7.98. When the ordinate of the control point is y = 60, y = 80, and y = 100, the gas flow will still separate at the end of the expansion section, but as the ordinate of the control point increases, the location of the flow separation gradually moves towards the end of the expansion section. However, when the ordinate of the control point is y = 120, y = 140, and y = 160, the gas flow can maintain its flow state along the wall in the expansion section until it leaves, and no flow separation will occur.

[0084] However, when the ordinate of the control point is greater than y = 160, the gas flow will separate at the head of the expansion section, and the maximum Mach number that can be achieved will drop significantly, even below the original model's Mach 7.73. Furthermore, as the ordinate of the control point increases, the maximum Mach number that can be achieved also decreases. This is because when the ordinate of the control point is large, the curve will deform significantly, and the initial expansion half-angle of the expansion section will also increase, resulting in a large adverse pressure gradient in the first half of the expansion section, preventing the gas flow from maintaining an expanded state along the wall.

[0085] In summary, the optimization design of the pneumatic device's surface profile has achieved certain results. Compared with the original surface profile curve, the deformed curve has better performance. Furthermore, through comparison of different deformed curves, it was found that the surface profile curve with the control point ordinate of y=160 has the best performance.

[0086] Table 1 Maximum Mach numbers corresponding to different control point ordinates

[0087]

[0088] The present invention proposes a non-parametric profile optimization design method for aerodynamic devices based on node offset technology, and provides a detailed introduction thereof, including an offset operator for changing the shape of a curve, a transition operator for transitioning an undeformed curve to a deformed curve, and a node offset method for deforming meshes in partial regions, and further gives some examples for illustration. The advantage of this profile optimization design method is that, without re-establishing the model and dividing meshes, it can deform the model profile relatively quickly and generate mesh files for calculation.

[0089] Meanwhile, the method is used to optimize a partial profile of a certain aerodynamic device, 10 mesh files containing different profile curve shapes are generated, imported into Fluent for flow field numerical simulation, and the results are compared and analyzed. The obtained conclusions are as follows:

[0090] 1) Compared with the original profile, the optimized aerodynamic device profile has better performance, and the maximum Mach number achievable after gas expansion increases from 7.73 Mach to 7.98 Mach.

[0091] 2) If the ordinate range of the control point is 160 < y < 240, when y = 160, the aerodynamic device profile has the best performance, and the maximum Mach number after gas expansion can reach 7.98 Mach; when y < 160, as the ordinate of the control point increases, the performance of the aerodynamic device profile gradually improves; when y > 160, as the ordinate of the control point increases, the performance of the aerodynamic device profile gradually decreases due to flow separation.

[0092] The present invention also provides an aerodynamic device profile optimization device, comprising a mesh division module, a profile optimization module and a profile selection module.

[0093] The mesh division module is configured to perform mesh division on the model of the original aerodynamic device to obtain a mesh file of the original aerodynamic device.

[0094] The profile optimization module is configured to select a region to be deformed in the mesh file of the original aerodynamic device, and obtain the original curve function of the region to be deformed; determine a set of deformation parameters including different mesh node coordinate offset amounts, configure multiple sets of offset operators and transition operators for the set of deformation parameters, multiply each set of offset operators and transition operators and superimpose the product onto the original curve function to obtain different deformed curve functions, so that the mesh of the region to be deformed is deformed, and a plurality of mesh files with different curve styles are generated; the offset operator and the transition operator are functions that enable the deformed curve to be continuous and smooth.

[0095] The profile selection module is used to perform flow field numerical simulations of different mesh files under the same computational conditions, obtain the flow parameters of each mesh file, compare the flow parameters of each mesh file, and select the profile with the best performance based on the comparison results.

[0096] Each module in the aforementioned pneumatic device profile optimization device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0097] Meanwhile, the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps in the method embodiment for optimizing the profile of a pneumatic device model. Specific implementation methods can be found in the method embodiment, and will not be repeated here.

[0098] Furthermore, the present invention also provides a non-transitory computer-readable storage medium containing instructions on which a computer program is stored. For example, a memory containing instructions that can be executed by a processor of a computer device to perform the above-described method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc. When the computer program is executed by the processor, it can implement the steps in the method embodiment for optimizing the surface of a pneumatic device model. Specific implementation methods can be found in the method embodiments, which will not be repeated here.

[0099] The non-parametric surface optimization design method of this invention is based on node offset technology. It does not act on the surface curve, meaning it does not require knowledge of the original surface curve function. Instead, it directly acts on the mesh file, causing deformation of the mesh in a certain region, thereby deforming the surface. This allows for the generation of a new mesh file for calculation without rebuilding the model and re-meshing the mesh.

[0100] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0101] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0102] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0103] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0104] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail in this specification and embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention; and all technical solutions and improvements that do not depart from the spirit and scope of the present invention are covered within the protection scope of the patent of the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for optimizing the profile of a pneumatic device model, characterized in that, Includes the following steps: The original pneumatic device model is meshed to obtain the mesh file of the original pneumatic device; Select the region to be deformed from the original pneumatic device mesh file and obtain the original curve function of the region to be deformed; determine a set of deformation parameters containing different mesh node coordinate offsets, and configure multiple sets of offset operators and transition operators for this set of deformation parameters. Multiply each set of offset operators and transition operators and then superimpose them onto the original curve function to obtain different deformed curve functions, thereby deforming the mesh of the region to be deformed and generating multiple mesh files with different curve styles; the offset operators and transition operators are functions that make the deformed curves continuous and smooth. Numerical simulations of the flow field were performed using different grid files under the same computational conditions to obtain the flow parameters of each grid file. The flow parameters of each grid file were then compared, and the best-performing profile was selected based on the comparison results.

2. The method for optimizing the profile of a pneumatic device model according to claim 1, characterized in that, The deformed curve function is: y(x)=y0(x)+d(x)*s(x) Where y0(x) is the original curve function, y(x) is the transformed curve function, d(x) is the offset operator, and s(x) is the transition operator.

3. The method for optimizing the profile of a pneumatic device model according to claim 2, characterized in that, The offset operator is any one of a constant function, a linear function, a quadratic function, or a spline curve function.

4. The method for optimizing the profile of a pneumatic device model according to claim 3, characterized in that, The transition operator is a piecewise function composed of a normalized sin function and a constant function y(x) = 1.

5. The method for optimizing the profile of a pneumatic device model according to claim 4, characterized in that, The transition operator and the offset operator are multiplied, with the ordinate interval [0,1]. The form of the multiplication of the transition operator and the offset operator is as follows: In the formula, x1 and x4 are the left and right endpoints of the x-coordinate interval of the deformed part of the curve, respectively, and x2 and x3 are the left and right endpoints of the x-coordinate interval of the fully deformed segment, respectively. When x < x1, s(x) remains 0, that is, the offset operator cannot provide any change, and the curve does not deform. When x1 ≤ x < x2, s1(x) gradually increases from 0 to 1, the change provided by the offset operator is limited, the curve begins to deform, and gradually transitions from the original curve to the deformed curve, which is called the transition segment. When x2 ≤ x ≤ x3, s(x) equals 1, the offset operator provides all the change, and this segment is called the fully deformed segment. When x3 < x ≤ x4, s2(x) gradually decreases from 1 to 0, the change provided by the offset operator is limited, and the curve gradually transitions from the deformed curve to the original curve again. When x > x4, s(x) remains 0, the offset operator cannot provide any change, and the curve does not deform.

6. The method for optimizing the profile of a pneumatic device model according to claim 5, characterized in that, Before obtaining the different deformed curve functions, the process also includes normalizing the abscissa of the transition operator.

7. A surface optimization device for a pneumatic device model, characterized in that, include: The mesh generation module is used to generate a mesh from the original pneumatic device model to obtain the mesh file of the original pneumatic device. The surface optimization module is used to select the region to be deformed in the original aerodynamic device mesh file and obtain the original curve function of the region to be deformed; determine a set of deformation parameters containing different mesh node coordinate offsets, and configure multiple sets of offset operators and transition operators for this set of deformation parameters. After multiplying each set of offset operators and transition operators, the results are superimposed on the original curve function to obtain different deformed curve functions, thereby deforming the mesh of the region to be deformed and generating multiple mesh files with different curve styles; the offset operators and transition operators are functions that make the deformed curves continuous and smooth. The profile selection module is used to perform flow field numerical simulations of different mesh files under the same computational conditions, obtain the flow parameters of each mesh file, compare the flow parameters of each mesh file, and select the profile with the best performance based on the comparison results.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is loaded by the processor, it is able to perform the steps of the method according to any one of claims 1 to 6.

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