Intelligent design system and method for aviation airborne porous system complex flow channel shell part

Abstract

The invention discloses an intelligent design system and method for an aviation airborne porous system complex flow channel shell part, and relates to the technical field of intelligent design, and the system comprises a data obtaining module which is used for obtaining a three-dimensional flow channel shell model, a working condition parameter set and a manufacturing limit; the feature extraction and arrangement band generation module is used for generating a candidate arrangement band; the hole group design and optimization module is used for generating a circumferential shallow cavity communication scheme and hole group arrangement; the acoustic impedance synthesis module is used for constructing equivalent surface complex impedance; the performance index calculation and association module is used for constructing system insertion loss and system additional voltage drop indexes; the multi-target tradeoff and solution verification module is used for obtaining a definite solution; and the design and manufacturing output module is used for taking the determined solution as parameterized computer aided design data and formulating manufacturing key points. According to the method, the arrangement area can be accurately selected in the complex flow channel, the controlled hole group can be constructed, and both noise attenuation and flow loss are considered.

Description

Technical Field

[0001] This invention relates to the field of intelligent design technology, and in particular to an intelligent design system for complex flow channel housing parts with porous systems for airborne applications. Background Technology

[0002] In airborne environments, flow channel shell components typically undertake complex aerodynamic and acoustic functions, requiring both stable delivery of high-speed airflow and noise reduction and aerodynamic loss control within limited installation space. As modern aircraft impose increasingly stringent requirements on cabin noise and structural weight, porous liners have gained widespread attention due to their ability to achieve broadband noise attenuation through pore groups and back cavity structures. However, flow channel shells often possess complex geometric features such as sharp bends and gently expanding cross-sections, leading to significant static pressure differentials near the inner walls. When this static pressure difference is superimposed on the gas exchange effect of the pore groups, it can cause severe imbalances in flow distribution within the pore groups, resulting in problems such as flow asymmetry, localized noise amplification, and increased additional aerodynamic drag. These phenomena not only weaken noise reduction effects but can also cause system-level performance degradation, such as excessive engine envelope noise or a decrease in overall aerodynamic efficiency.

[0003] In existing technologies, traditional design methods typically rely on uniformly distributed orifice groups or empirical formulas for arrangement. These methods fail to fully utilize the actual static pressure difference distribution within the flow channel. When orifice groups are arranged solely based on geometric parameters while ignoring the effect of local static pressure differences, some areas of the orifice group may experience excessive flow exchange, leading to localized flow overload, while other areas remain inefficient. This not only disrupts the overall flow and acoustic harmony but also significantly increases the additional pressure drop, thereby reducing the system's stability and reliability under actual flight conditions. Therefore, establishing a design method that balances noise reduction performance with additional pressure drop control, and avoids flow distribution imbalances in complex flow channels, has become a core problem that urgently needs to be solved in the design of such components. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies in effectively controlling the additional flow resistance introduced by the pore group while ensuring noise attenuation in complex flow channel environments. Therefore, this invention proposes an intelligent design system and method for complex flow channel shell parts with porous systems for airborne applications.

[0005] To address the problems existing in the prior art, the present invention adopts the following technical solution: An intelligent design system for complex flow channel housing parts with porous systems for airborne applications, comprising: The data acquisition module is used to acquire the three-dimensional flow channel shell model, working condition parameter set, and manufacturing limits; The feature extraction and layout strip generation module is used to extract the centerline arc length and determine the radius of curvature distribution from the three-dimensional flow channel shell model, and generate candidate layout strips based on the inner curved wall and the post-bend expansion section of the three-dimensional flow channel shell model. The static pressure analysis and priority area screening module is used to determine the circumferential static pressure difference along the centerline arc length within the candidate layout zone based on the curvature radius distribution and the set of working parameters, and to screen out the priority layout zone based on the circumferential static pressure difference. The orifice group design and optimization module is used to construct circumferentially connected shallow cavities in the priority arrangement area, group the orifices in the circumferentially connected shallow cavities, determine the single-orifice volumetric flow rate of each orifice based on the circumferential static pressure difference, and generate the circumferential shallow cavity connection scheme and orifice group arrangement based on the single-orifice volumetric flow rate. The acoustic impedance synthesis module is used to calculate the aperture impedance and shallow cavity capacitive reactance based on the circumferential shallow cavity connectivity scheme and aperture group arrangement, and synthesize the aperture impedance and shallow cavity capacitive reactance into an equivalent surface complex impedance. The performance index calculation and correlation module is used to calculate the system insertion loss based on the equivalent surface complex impedance, calculate the system additional pressure drop based on the single-hole volumetric flow rate, combine the system insertion loss and the system additional pressure drop into index pairs and correlate them with their corresponding design variable sets. The multi-objective trade-off and solution verification module is used to form a trade-off curve on the index pair plane of system additional voltage drop and system insertion loss, and to use the curvature maxima of the geometric inflection point of the trade-off curve as candidate solutions, and to perform consistency verification on the candidate solutions to obtain the definite solution; The design and manufacturing output module is used to take the determined solution as parametric computer-aided design data and formulate manufacturing points.

[0006] Preferably, obtaining the three-dimensional flow channel shell model, operating parameter set, and manufacturing limits includes: The three-dimensional flow channel shell model, operating parameter set, and manufacturing limits are obtained. The operating parameter set includes gas density, dynamic viscosity, near-wall representative velocity, and sound velocity. The manufacturing limits include the range of hole radius and the range of base material wall thickness. The coordinates and units of the three-dimensional flow channel shell model are then unified.

[0007] Preferably, the centerline arc length is extracted from the three-dimensional flow channel shell model and the radius of curvature distribution is determined. Candidate arrangement zones are generated based on the inner curved wall and the post-bend gradual expansion section of the three-dimensional flow channel shell model, including: The centerline of the inner cavity is extracted from the three-dimensional flow channel shell model, and the arc length is obtained by spline fitting and parameterization according to the arc length. The curvature of the centerline arc length is calculated based on equidistant sampling to obtain the curvature radius distribution; Establish a local orthogonal system at each sampling section to determine the inner curved wall, and record the radius difference between the inner and outer curves to the center line; Under the condition of meeting the manufacturing limit, a strip-shaped region is formed by expanding the inner wall of the bend, and a strip-shaped region is added as a post-bend gradual expansion section in the section where the cross-sectional area increases gradually after the bend. The intersection of the inner curved wall strip and the post-bend gradual expansion section is selected as the candidate layout zone.

[0008] Preferably, within the candidate arrangement zone, the circumferential static pressure difference along the centerline arc length is determined based on the radius of curvature distribution and the set of operating parameters, and a preferred arrangement area is selected based on the circumferential static pressure difference, including: Within the candidate arrangement zone, the circumferential static pressure difference is approximately calculated by centrifugal equilibrium based on the curvature radius distribution, near-wall representative velocity, gas density, and the difference in the inner and outer bending radii of the cross section along the arc length of the centerline. The priority layout area is obtained by taking the local maximum value of the circumferential static pressure difference as the center and the adjacent local minimum values ​​as the interval boundary.

[0009] Preferably, a circumferentially connected shallow cavity is constructed within the priority arrangement area. The orifices within the circumferentially connected shallow cavity are grouped, and the single-orifice volumetric flow rate of each orifice is determined based on the circumferential static pressure difference. Based on the single-orifice volumetric flow rate, a circumferentially connected shallow cavity scheme and orifice group arrangement are generated, including: Within the priority layout area, a continuous circumferential shallow cavity ring is constructed along the circumference of the flow channel according to manufacturing limits; Based on the high-pressure side and low-pressure side of the circumferential static pressure difference, the holes are arranged in groups from the high-pressure side to the low-pressure side. Calculate the volumetric flow rate of a single orifice based on orifice radius, orifice flow coefficient and circumferential static pressure difference; By applying zero net mass exchange constraints to each cross section of the flow channel inside the shell, and by adjusting the number of holes and the pairing method of the holes, the algebraic sum of the volumetric flow rate of a single hole in the cross section is made zero, thus obtaining the circumferential shallow cavity connection scheme and hole group arrangement.

[0010] Preferably, based on the circumferential shallow cavity connectivity scheme and the arrangement of the hole group, the hole impedance and shallow cavity capacitive reactance are calculated, and the hole impedance and shallow cavity capacitive reactance are combined into an equivalent surface complex impedance, including: Based on the circumferential shallow cavity connection scheme and the hole group arrangement, the opening ratio was statistically analyzed, and the hole axis inclination angle, base material wall thickness, hole radius, shallow cavity volume, lining surface area, angular frequency, gas density, sound velocity and dynamic viscosity were obtained. The base material wall thickness is geometrically stretched according to the hole axis inclination angle, and the end corrections at both ends of the hole are superimposed to obtain the equivalent thickness of the hole; The pore impedance is calculated based on the Maa approximation and in combination with equivalent thickness, porosity, pore radius, dynamic viscosity, gas density, and angular frequency. The volume of the back cavity per unit area is obtained by the ratio of the shallow cavity volume to the lining surface area. Calculate the shallow cavity capacitive reactance based on gas density, sound velocity, angular frequency, and back cavity volume per unit area; The equivalent surface complex impedance is obtained by superimposing the aperture impedance and shallow cavity capacitive reactance at the same centerline arc length and the same angular frequency.

[0011] Preferably, the system insertion loss is calculated based on the equivalent surface complex impedance, and the system additional pressure drop is calculated based on the single-orifice volumetric flow rate. The system insertion loss and system additional pressure drop are combined into an index pair and associated with their corresponding set of design variables, including: Dividing the equivalent surface complex impedance by the product of the gas density and the sound velocity yields the dimensionless impedance. The absorption coefficient is obtained by calculating the normal incident absorption coefficient of the dimensionless impedance; The sound absorption coefficient is obtained by wideband arithmetic mean. The average sound absorption coefficient is then calculated by inserting the average sound absorption coefficient and weighted and summed with the center line arc length to obtain the system insertion loss. The orifice area is calculated based on the orifice radius. The gas flow rate of the orifice is obtained by dividing the volumetric flow rate of a single orifice by the orifice area. Based on the gas flow rate and gas density, the local additional pressure drop of each orifice is obtained. The additional pressure drop of the system is obtained by superimposing the local additional pressure drops of all the holes; The system insertion loss and system additional pressure drop are combined into a performance index pair, and their corresponding hole axis tilt angle, opening ratio, back cavity volume per unit area, circumferential shallow cavity connectivity scheme and hole group arrangement are associated.

[0012] Preferably, a tradeoff curve is formed on the index pair plane of system additional pressure drop and system insertion loss, and the curvature maxima of the geometric inflection point of the tradeoff curve are used as candidate solutions. Consistency checks are performed on the candidate solutions to obtain a definite solution, including: Plot index points with the system additional voltage drop as the horizontal axis and the system insertion loss as the vertical axis, and filter the index points: retain index points that do not have another index pair that satisfy both a smaller system additional voltage drop and a larger system insertion loss; The retained indicators are sorted in ascending order of system additional pressure drop, and a continuous trade-off curve is obtained by cubic spline fitting. The geometric inflection point of each point is obtained based on the discrete curvature of three adjacent points, and the point with the maximum curvature is taken as a candidate solution. The circumferential static pressure difference corresponding to the candidate solution is used to back-calculate the single-hole volumetric flow rate of each section to verify the zero net mass exchange constraint. At the same time, the equivalent surface complex impedance, insertion loss and additional pressure drop are recalculated for the design variable set associated with the candidate solution. If they are inconsistent with the inflection point index, the hole axis inclination angle, opening ratio, back cavity volume per unit area or hole pairing relationship are adjusted locally in the corresponding section and the verification is repeated until the inflection point index is met to obtain the definite solution.

[0013] Preferably, the determined solution is used as parametric computer-aided design data and manufacturing points are formulated, including: The design parameters in the determined solution are associated with the three-dimensional model of the flow channel shell to generate a fully parametric three-dimensional CAD model; Based on the characteristics of additive manufacturing processes and the geometric features of deterministic solutions, key manufacturing points are given, including: build direction, support and powder removal channels, and inaccessible areas.

[0014] To address the aforementioned problems, this invention also provides an intelligent design method for complex flow channel housing parts with porous systems used in aerospace applications, the method comprising: S1. Obtain the three-dimensional flow channel shell model, working condition parameter set, and manufacturing limits; S2. Extract the centerline arc length from the three-dimensional flow channel shell model and determine the radius of curvature distribution. Generate candidate arrangement zones based on the inner curved wall and the post-bend expansion section of the three-dimensional flow channel shell model. S3. Within the candidate arrangement zone, determine the circumferential static pressure difference along the arc length of the centerline based on the curvature radius distribution and the set of working parameters, and select the priority arrangement area based on the circumferential static pressure difference. S4. Construct circumferentially connected shallow cavities within the priority arrangement area, group the holes in the circumferentially connected shallow cavities, determine the single-hole volumetric flow rate of each hole based on the circumferential static pressure difference, and generate the circumferentially connected shallow cavity scheme and hole group arrangement based on the single-hole volumetric flow rate. S5. Based on the circumferential shallow cavity connection scheme and the arrangement of the hole group, calculate the hole impedance and shallow cavity capacitive reactance, and combine the hole impedance and shallow cavity capacitive reactance into an equivalent surface complex impedance. S6. Calculate the system insertion loss based on the equivalent surface complex impedance, calculate the system additional pressure drop based on the single-hole volumetric flow rate, combine the system insertion loss and the system additional pressure drop into an index pair and associate them with their corresponding set of design variables. S7. Form a trade-off curve on the index pair plane of system additional pressure drop and system insertion loss, and take the curvature maxima of the geometric inflection point of the trade-off curve as the candidate solution. Perform consistency check on the candidate solutions to obtain the definite solution. S8. Use the determined solution as parametric computer-aided design data and formulate manufacturing points.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, by extracting the arc length of the centerline and determining the radius of curvature distribution within the complex flow channel shell, and combining the inner curved wall and the post-bend slow expansion section to generate a candidate arrangement zone, the arrangement of the orifice group can accurately correspond to the local static pressure difference distribution, thereby avoiding the flow distribution imbalance caused by the traditional uniform orifice arrangement method. Through this method, the effective arrangement area can be defined in the initial design stage, making the working state of the orifice group more stable and improving the utilization efficiency of the noise attenuation structure.

[0016] 2. In this invention, by calculating the circumferential static pressure difference within the candidate arrangement zone and constructing a shallow back cavity with circumferential connectivity accordingly, and simultaneously applying a zero net mass exchange constraint at the cross-section, the algebraic sum of the volumetric flow rates of the orifice group at each cross-section is zero, thus eliminating the problem of local orifice group flow overload. This design method not only controls the gas exchange distribution of the orifice group but also ensures the overall flow balance, thereby effectively reducing the adverse effects of the additional pressure drop on the aerodynamic performance of the system.

[0017] 3. In this invention, an equivalent surface complex impedance model of orifice impedance and shallow cavity capacitive reactance is established, and the system insertion loss is calculated based on this impedance model. This loss is then compared with the additional pressure drop of the system calculated from the single-orifice volumetric flow rate to form an index. Finally, a unique preferred solution is selected through a trade-off curve. This process enables the acoustic and aerodynamic performance to be optimized under the same evaluation system, ensuring that the designed porous complex flow channel shell parts have both wide-band noise attenuation capability and low flow loss in practical applications, thereby significantly improving the overall system's operational stability and reliability. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 A functional block diagram of an intelligent design system for a complex flow channel housing component of an airborne porous system provided in an embodiment of the present invention; Figure 2 This is a flowchart illustrating an intelligent design method for a complex flow channel housing component with a porous system for airborne applications, as provided in an embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Example: This example provides an intelligent design system for complex flow channel housing parts with porous systems for airborne applications. See [link to example]. Figure 1 Specifically, including: The data acquisition module is used to acquire the three-dimensional flow channel shell model, working condition parameter set, and manufacturing limits; In embodiments of the present invention, obtaining the three-dimensional flow channel shell model, the set of operating parameters, and manufacturing limits includes: The three-dimensional flow channel shell model, working condition parameter set, and manufacturing limits are obtained. The working condition parameter set includes gas density, dynamic viscosity, near-wall representative velocity, and sound speed. The manufacturing limits include the range of hole radius and the range of base material wall thickness. The coordinates and units of the three-dimensional flow channel shell model are unified. Specifically, a three-dimensional flow channel shell model of a complex porous flow channel shell component for airborne applications is obtained. This model is the original three-dimensional model generated during the flow channel shell design phase, containing the complete internal structure of the flow channel. The model format adopts the STEP format commonly used in the engineering field. Simultaneously, a set of operating parameters is obtained. Gas density and dynamic viscosity parameters are obtained based on typical operating conditions in airborne environments, according to relevant aviation industry standards. Near-wall representative velocity parameters are calculated by combining the design flow rate of the flow channel system with the flow channel cross-sectional dimensions. Sound velocity parameters are calculated based on the temperature and composition of the working medium within the flow channel, using relevant gas dynamics formulas. Manufacturing limit parameters are also obtained. The hole radius range parameter is determined based on the minimum hole diameter processing capability and maximum hole diameter design constraints of the selected additive manufacturing equipment. The base material wall thickness range parameter is based on the additive manufacturing equipment's... In the material manufacturing process, the minimum wall thickness forming limit and structural strength requirements of the base material are determined. The obtained three-dimensional flow channel shell model is processed to unify the coordinates and units. The coordinate system is set with the origin of the flow channel centerline as the origin, the tangent direction of the flow channel centerline as the X-axis, the radial direction of the flow channel cross-section as the Y-axis, and the circumferential direction of the flow channel cross-section as the Z-axis to establish a right-hand rectangular coordinate system. The unit system is uniformly adopted with the International System of Units (SI) derivative system, which uses millimeters for length, kilograms per cubic meter for density, Pascals per second for viscosity, and meters per second for velocity. Through the coordinate transformation and unit conversion functions of the three-dimensional modeling software, the three-dimensional flow channel shell model is adjusted to a unified coordinate system and unit system to ensure that the data used in subsequent steps such as flow channel geometric feature extraction and circumferential static pressure difference calculation have a consistent coordinate and unit reference.

[0021] The feature extraction and layout strip generation module is used to extract the centerline arc length and determine the radius of curvature distribution from the three-dimensional flow channel shell model, and generate candidate layout strips based on the inner curved wall and the post-bend expansion section of the three-dimensional flow channel shell model. In an embodiment of the present invention, the centerline arc length is extracted from the three-dimensional flow channel shell model and the radius of curvature distribution is determined. Candidate arrangement zones are generated based on the inner curved wall and the post-bend gradual expansion section of the three-dimensional flow channel shell model, including: The centerline of the inner cavity is extracted from the three-dimensional flow channel shell model, and the arc length is obtained by spline fitting and parameterization according to the arc length. Specifically, a 3D flow channel shell model with unified coordinates and units is imported into the 3D modeling software. The internal cavity region of the flow channel shell is selected using the software's cavity extraction function, and all curved surfaces constituting the internal cavity wall are filtered out to form a closed internal cavity boundary model. Multiple cross-sections perpendicular to the flow channel direction are selected at 0.5 mm intervals along the flow channel length. Each cross-section intersects the internal cavity wall to form a closed cross-sectional profile. The geometric center calculation function of the software is used to obtain the geometric center of each cross-sectional profile. The geometric centers of all cross-sections are connected sequentially according to the flow channel direction to form the initial discrete point sequence of the internal cavity centerline. A cubic spline fitting algorithm is used to refine the initial discrete points. The point sequence is fitted with a curve, and a smooth continuous curve is constructed using the coordinates of adjacent discrete points as constraints. This ensures that the deviation between the fitted curve and the initial point sequence is controlled within the flow channel design tolerance. This fitted curve is the inner cavity centerline of the flow channel. The inner cavity centerline obtained by fitting is then parameterized by arc length. Taking one of the endpoints of the centerline as the starting point, the curve is discretized into multiple tiny line segments along the centerline. The length of each line segment is calculated by the numerical integration function of the software and accumulated sequentially to obtain the cumulative length from the starting point to any point on the centerline. This cumulative length is the arc length of the corresponding point. At the same time, a table of correspondence between the arc length and the coordinates of each point on the centerline is generated.

[0022] The curvature of the centerline arc length is calculated based on equidistant sampling to obtain the curvature radius distribution; Specifically, based on the inner cavity centerline and the generated table of arc length and coordinate correspondence, an equidistant sampling interval is determined. This interval, combined with the total length of the flow channel and accuracy requirements, is set to 0.5 mm to ensure that the sampling points cover the entire centerline and reflect the curvature characteristics of the curve. Sampling points are selected sequentially along the arc length direction of the centerline at the set intervals, and the arc length value of each sampling point and its three-dimensional coordinates in a unified coordinate system are recorded to form an equidistant sampling point dataset containing arc length, X coordinate, Y coordinate, and Z coordinate. The first and second derivatives of the curve at each sampling point are calculated using the five-point numerical differentiation method. Taking any target sampling point as the center, two adjacent sampling points before and after it are selected. An approximate function of the centerline in this region is constructed using a Lagrange interpolation polynomial, and the first and second derivatives of the approximate function are calculated respectively. The first derivative is used to obtain the tangent direction vector and the rate of change of curvature vector at the target sampling point. Then, according to the curvature calculation formula of the space curve, the magnitudes of the first and second derivative vectors of the target sampling point are substituted into the formula to calculate the curvature value at that sampling point. The curvature calculation formula is the ratio of the magnitude of the second derivative vector to the cube of the magnitude of the first derivative vector. The reciprocal of the curvature value calculated for each sampling point is taken to obtain the radius of curvature corresponding to each sampling point. For the segment in the center line that is approximately a straight line, its radius of curvature is set to infinity to conform to the geometric characteristics of a straight line segment. Finally, the arc length values ​​and corresponding radii of curvature of each sampling point are arranged in ascending order of arc length to form a one-to-one correspondence table between arc length and radius of curvature. This relationship is the distribution table of arc length and radius of curvature of the center line.

[0023] Establish a local orthogonal system at each sampling section to determine the inner curved wall, and record the radius difference between the inner and outer curves to the center line; Specifically, the geometric analysis function of 3D modeling software is used to locate the intersection point of each sampling section and the centerline of the inner cavity. This intersection point is the origin of the local orthogonal system for the corresponding sampling section. The X-axis of the local orthogonal system is determined based on the tangent direction of the centerline at this intersection point. The tangent direction is calculated using the first derivative of the centerline. Then, the Y-axis of the local orthogonal system is determined by the direction perpendicular to the sampling section and passing through the origin. Finally, according to the right-hand screw rule, the Z-axis of the local orthogonal system is obtained by the cross product of the X-axis and Y-axis, thus completing the establishment of the local orthogonal system for each sampling section. Combining the arc length and radius of curvature distribution of the centerline, the direction of the center of curvature of the centerline at that sampling section is calculated. The direction of the center of curvature is determined by the relationship between the second derivative and the first derivative of the centerline. Along the Y-axis direction of the local orthogonal system, the wall surface of the sampling section closest to the center of curvature is... The wall surface of the sampling section on the side furthest from the center of curvature is determined to be the inner curved wall, and the wall surface of the sampling section is determined to be the outer curved wall. According to the cross-sectional dimensions, multiple measurement points are uniformly selected circumferentially on the inner curved wall of the sampling section. The distance measurement function of the 3D modeling software is used to calculate the distance from each measurement point to the origin of the local orthogonal system. The arithmetic mean of these distances is taken as the radius of the inner curve to the center line. The same method is used to uniformly select the same number of measurement points circumferentially on the outer curved wall of the sampling section. The distance from each measurement point to the origin is calculated and the arithmetic mean is taken as the radius of the outer curve to the center line. Finally, the radius difference between the inner and outer curves to the center line is obtained by subtracting the radius of the outer curve from the radius of the inner curve to the center line. The radius difference of each sampling section is recorded in the order of the arc length of the sampling section to form a corresponding dataset of inner and outer curve radius differences and arc lengths.

[0024] Under the condition of meeting the manufacturing limit, a strip-shaped region is formed by expanding the inner wall of the bend, and a strip-shaped region is added as a post-bend gradual expansion section in the section where the cross-sectional area increases gradually after the bend. The intersection of the inner curved wall strip and the post-bend widening section is considered as a candidate arrangement zone. Specifically, the parameters of the base material wall thickness and hole radius range within the manufacturing limits are obtained, and the geometric constraints that must be met during the expansion of the strip region are clarified. That is, the minimum width of the strip region must not be less than twice the hole radius to ensure sufficient space when arranging the hole group, and the maximum width must not be greater than three times the base material wall thickness to avoid exceeding the material forming capacity and causing insufficient structural strength. Based on the determined range of the inner curved wall and the local orthogonal system of each sampling section, the spatial contour of the inner curved wall is located in the 3D modeling software. Taking the geometric center of the inner curved wall of each sampling section as the reference, the strip region is expanded along the direction perpendicular to the inner curved wall surface in the local orthogonal system. During the expansion process, the real-time dimension monitoring function of the software is used to ensure that the width of the strip region at each arc length position is within the range allowed by the manufacturing limits. At the same time, the interference check function of the software is used to check whether the expanded strip region interferes with other structures of the flow channel shell, such as reinforcing ribs. If there is a spatial conflict with the interface flange, the width of the expansion is locally adjusted until a continuous and conflict-free inner curved wall strip area is formed. Then, the section with a gradually increasing cross-sectional area after the bend is identified. By calculating the flow channel cross-sectional area of ​​adjacent sampling sections, the gradual increase of the cross-sectional area is set to the point where the growth rate of the adjacent cross-sectional area does not exceed 5%. All arc length sections that meet this condition are selected as the sections with a gradually increasing cross-sectional area after the bend. On the wall surface of this section, the same expansion principle as the inner curved wall strip area is applied to expand along the wall normal to form an additional strip area. During the expansion process, the width of the additional strip area is kept consistent with that of the inner curved wall strip area, and the curve smoothing function of the software is used to make the transition between the two strip areas continuous. Finally, the inner curved wall strip area and the additional strip area after the bend are integrated to form a complete candidate arrangement strip initial outline. The arc length range and three-dimensional coordinates of this outline are marked in the 3D modeling software.

[0025] The static pressure analysis and priority area screening module is used to determine the circumferential static pressure difference along the centerline arc length within the candidate layout zone based on the curvature radius distribution and the set of working parameters, and to screen out the priority layout zone based on the circumferential static pressure difference. In an embodiment of the present invention, within the candidate arrangement zone, the circumferential static pressure difference along the centerline arc length is determined based on the radius of curvature distribution and the set of operating parameters, and a preferred arrangement area is selected based on the circumferential static pressure difference, including: Within the candidate arrangement zone, the circumferential static pressure difference is approximately calculated by centrifugal equilibrium based on the curvature radius distribution, near-wall representative velocity, gas density, and the difference in the inner and outer bending radii of the cross section along the arc length of the centerline. Specifically, within the arc length coverage area of ​​the candidate arrangement zone, sampling points are divided along the arc length direction of the corresponding centerline of the candidate arrangement zone at equidistant sampling intervals of 0.5 mm. Each sampling point corresponds to a unique arc length position, and the arc length value of each sampling point and its corresponding radius of curvature and the difference between the inner and outer bending radii of the cross section are recorded. For each sampling point, the circumferential static pressure difference calculation relationship is constructed using the centrifugal equilibrium approximation principle. The formula for calculating the circumferential static pressure difference is:

[0026] In the formula, The arc length of the center line Circumferential static pressure difference at the location, For gas density, The near-wall representative velocity, The arc length of the center line The radius of curvature at that point The difference between the inner and outer bending radii of the cross section; After calculating the circumferential static pressure difference for all sampling points, the calculation results are processed by the data smoothing module. Linear interpolation is used to fill the gaps in the circumferential static pressure difference data between adjacent sampling points to ensure the continuous distribution of the circumferential static pressure difference along the arc length of the centerline. At the same time, outliers exceeding the physically reasonable range are removed. The criteria for judging outliers is that the circumferential static pressure difference of a sampling point exceeds 20% of the average value of five adjacent sampling points. A correspondence table between the circumferential static pressure difference and the position of the arc length of the centerline is generated. In the 3D modeling software, the circumferential static pressure difference values ​​at each arc length position are associated and marked with the spatial position of the candidate arrangement zone to obtain the circumferential static pressure difference distribution covering the entire candidate arrangement zone.

[0027] The priority layout area is obtained by taking the local maximum value of the circumferential static pressure difference as the center and the adjacent local minimum values ​​as the interval boundary; Specifically, the circumferential static pressure difference data is preprocessed using a moving average method to smooth the data. The window size is 6 consecutive sampling points to eliminate high-frequency noise interference and ensure the continuity of the static pressure difference variation trend. Then, the smoothed circumferential static pressure difference data is traversed along the arc length of the centerline. Local extrema are determined by the change in the sign of the first derivative. When the first derivative at a sampling point changes from positive to negative, that point is identified as a local maximum; when it changes from negative to positive, that point is identified as a local minimum. The identified local maxima are sorted in arc length order. For each local maximum, the first adjacent local minimum along the arc length is found, and the forward adjacent local minimum is used as the interval. The starting boundary is defined by using the adjacent local minima as the interval termination boundary, forming a candidate interval centered on the local maximum. If the local maximum is located at the beginning of the data flow, the arc length corresponding to the beginning of the flow channel is used as the interval starting boundary; if it is located at the end of the data flow, the arc length corresponding to the end of the flow channel is used as the interval termination boundary. If the candidate intervals corresponding to adjacent local maximums overlap, the union of the overlapping areas is taken as the merged interval, and the center of the merged interval is the local maximum with the largest static pressure difference in the overlapping area. Finally, all candidate intervals or merged intervals are mapped to the candidate arrangement zone of the three-dimensional flow channel shell model, and the spatial regions corresponding to these intervals are marked as the priority arrangement areas.

[0028] The orifice group design and optimization module is used to construct circumferentially connected shallow cavities in the priority arrangement area, group the orifices in the circumferentially connected shallow cavities, determine the single-orifice volumetric flow rate of each orifice based on the circumferential static pressure difference, and generate the circumferential shallow cavity connection scheme and orifice group arrangement based on the single-orifice volumetric flow rate. In an embodiment of the present invention, within a priority arrangement area, a shallow cavity with circumferential connectivity is constructed based on manufacturing limits. The holes in the circumferentially connected shallow cavity are grouped, and the single-hole volumetric flow rate of each hole is determined based on the circumferential static pressure difference. A circumferential shallow cavity connectivity scheme and hole group arrangement are generated based on the single-hole volumetric flow rate, including: Within the priority layout area, a continuous circumferential shallow cavity is constructed along the circumference of the flow channel according to manufacturing limits; Based on the high-pressure side and low-pressure side of the circumferential static pressure difference, the holes are arranged in groups from the high-pressure side to the low-pressure side. Specifically, in the 3D modeling software, the wall area of ​​the priority placement zone is located. Along the circumferential direction of the flow channel, and limited by the circumferential boundary of the priority placement zone, the cross-sectional outline of the shallow cavity is drawn. The cross-sectional shape is rectangular to facilitate additive manufacturing. The cross-sectional depth is selected as 40% to 60% of the base material wall thickness, with the specific value dynamically adjusted according to the base material wall thickness at different arc length positions of the priority placement zone to ensure it does not exceed manufacturing limits. The cross-sectional width is selected as three to five times the hole radius to ensure it covers the circumferential range of the priority placement zone. Using the sweep function of the 3D modeling software, the drawn cross-sectional outline is swept along the arc length direction of the priority placement zone to form a continuous circumferential shallow cavity initial 3D structure. During the sweeping process, the cross-sectional parameters of the shallow cavity are kept to transition smoothly along the arc length direction. The rate of change of cross-sectional depth and width at adjacent locations should not exceed 10% to avoid stress concentration caused by abrupt changes. Then, the software's interference check function is used to check whether there is spatial overlap between the circumferential shallow cavity and other structures of the flow channel shell, such as internal supports and interface flanges. If interference exists, the circumferential boundary of the shallow cavity is locally adjusted. After adjustment, it must still be located within the priority arrangement area or the local cross-sectional size must be reduced. After adjustment, it must still meet the manufacturing limits until all interference is eliminated. Finally, the inner wall of the circumferential shallow cavity is rounded, with the rounded radius not less than half of the hole radius to reduce stress concentration. A continuous 3D model of the circumferential shallow cavity that meets the manufacturing limits is generated. This model is integrated with the basic model of the flow channel shell through Boolean operations to output an intermediate model of the flow channel shell containing the circumferential shallow cavity.

[0029] In detail, the boundaries between the high-pressure and low-pressure sides at each arc length are determined through static pressure difference contour analysis. The high-pressure side is the region with a higher circumferential static pressure difference, and the low-pressure side is the region with a lower circumferential static pressure difference. The division between the two is based on the direction of the static pressure difference gradient; that is, the direction from high to low gradient is the direction from the high-pressure side to the low-pressure side. Simultaneously, the hole radius range parameter in the manufacturing limits is extracted, clarifying that the minimum spacing between holes must not be less than twice the hole radius to avoid insufficient structural strength between holes. The number of holes in a single group does not exceed the ratio of the circumferential width of the shallow cavity to the hole diameter, ensuring a reasonable distribution of the hole group within the shallow cavity. This is then optimized for positioning in the 3D modeling software. First, the inner wall of the shallow cavity in the circumferential direction of the arrangement area is arranged. The hole arrangement axis is marked along the high-pressure side to the low-pressure side at each arc length position. The length of the axis does not exceed the circumferential width of the shallow cavity to ensure that the holes are completely located in the shallow cavity. The hole spacing is set at twice the hole radius. The center coordinates of each hole in a single group are determined sequentially along the arrangement axis. The holes are arranged linearly with equal spacing. The number of holes in a single group is an integer based on the ratio of the circumferential width of the shallow cavity to the hole diameter. The continuity of the hole groups at adjacent arc length positions is checked. By adjusting the starting position of the hole groups, the holes in adjacent groups are arranged in a continuous oblique arrangement in the arc length direction to avoid obvious misalignment of the hole groups in the arc length direction. Calculate the volumetric flow rate of a single orifice based on orifice radius, orifice flow coefficient and circumferential static pressure difference; Specifically, the determined orifice radius parameters and orifice flow coefficients are obtained. The orifice flow coefficient is selected based on the orifice processing characteristics. For orifices formed by additive manufacturing without chamfering, a coefficient value of 0.6 to 0.7 is used, while for orifices with chamfering after post-processing, a coefficient value of 0.7 to 0.8 is used. The cross-sectional area of ​​the orifice is obtained according to the circular area calculation rules based on the orifice radius. The circumferential static pressure difference at each orifice location is extracted. The circumferential static pressure difference distribution is located using the three-dimensional coordinates of the orifice. The precise value of the static pressure difference at that location is calculated using the adjacent three-point interpolation method. The static pressure difference at the location corresponding to the high-pressure side orifice is recorded as the high-pressure value, and the static pressure difference at the location corresponding to the low-pressure side orifice is recorded as the low-pressure value. The static pressure difference driving value of a single orifice is the difference between the high-pressure value and the low-pressure value. The volumetric flow rate of a single orifice is obtained by applying the orifice flow calculation rules. The calculation process is to multiply the orifice flow coefficient by the cross-sectional area of ​​the single orifice, and then multiply it by the square root of the ratio of twice the static pressure difference driving value to the gas density. The volumetric flow rate of each orifice is calculated sequentially according to this rule.

[0030] By applying zero net mass exchange constraints to each cross section of the flow channel inside the shell, and by adjusting the number of holes and the pairing method of the holes, the algebraic sum of the volumetric flow rate of a single hole in the cross section is made zero, thus obtaining the circumferential shallow cavity communication scheme and hole group arrangement. Specifically, along the arc length of the flow channel centerline, at preset intervals (one-fifth to one-tenth of the flow channel diameter), multiple flow channel sections perpendicular to the centerline are defined based on the flow channel dimensions. Each section intersects with the circumferential shallow cavity and orifice group. The orifice identifiers and corresponding volumetric flow rates within each section are recorded. A zero net mass exchange constraint is applied to each flow channel section, and the algebraic sum of the volumetric flow rates of all orifices within that section is calculated. The flow rate of the high-pressure side orifices is taken as positive, and the flow rate of the low-pressure side orifices is taken as negative. If the absolute value of the algebraic sum is greater than 5% of the maximum single-orifice volumetric flow rate within the section, the orifices are adjusted. When adjusting the number of orifices, it should be within the manufacturing limit's allowable orifice radius range. If the algebraic sum is positive (i.e., the total flow rate on the high-pressure side is too large), the number of orifices on the low-pressure side is increased, or the radius of some orifices on the high-pressure side is decreased; if the algebraic sum is negative (i.e., the total flow rate on the low-pressure side is too large), the number of orifices on the low-pressure side is increased, or the radius of some orifices on the high-pressure side is decreased. If the total flow rate is too high, increase the number of orifices on the high-pressure side or reduce the radius of some orifices on the low-pressure side. After each adjustment, recalculate the volumetric flow rate of a single orifice and the algebraic sum of the cross-section until the absolute value of the algebraic sum is less than 5% of the maximum volumetric flow rate of a single orifice within the cross-section. When adjusting the orifice pairing method, regroup the orifice groups within the cross-section, pairing orifices with higher flow rates on the high-pressure side with orifices with higher flow rates on the low-pressure side, and pairing orifices with lower flow rates on the high-pressure side with orifices with lower flow rates on the low-pressure side, so that the absolute value deviation of the flow rate of each pairing group does not exceed 10%. Balance the total flow rate within the cross-section by adjusting the pairing combination. If the pairing adjustment still does not meet the constraint, adjust the number of orifices until the absolute value of the algebraic sum of the volumetric flow rate within the cross-section is close to zero. For orifice groups that meet the zero net mass exchange constraint within the same flow channel cross-section, set their corresponding shallow cavity regions as connected structures.

[0031] The acoustic impedance synthesis module is used to calculate the aperture impedance and shallow cavity capacitive reactance based on the circumferential shallow cavity connectivity scheme and aperture group arrangement, and synthesize the aperture impedance and shallow cavity capacitive reactance into an equivalent surface complex impedance. In embodiments of the present invention, the aperture impedance and shallow cavity capacitive reactance are calculated based on the circumferential shallow cavity connectivity scheme and the aperture group arrangement, and the aperture impedance and shallow cavity capacitive reactance are combined into an equivalent surface complex impedance, including: Based on the circumferential shallow cavity connection scheme and the hole group arrangement, the opening ratio was statistically analyzed, and the hole axis inclination angle, base material wall thickness, hole radius, shallow cavity volume, lining surface area, angular frequency, gas density, sound velocity and dynamic viscosity were obtained. The base material wall thickness is geometrically stretched according to the hole axis inclination angle, and the end corrections at both ends of the hole are superimposed to obtain the equivalent thickness of the hole; Specifically, the 3D model of the circumferential shallow cavity connectivity scheme, the 3D model of the hole group arrangement, and the lining surface area data of the priority arrangement area are obtained. First, the total cross-sectional area of ​​all holes in the hole group is calculated, and then the total cross-sectional area is divided by the lining surface area to obtain the opening ratio. Various parameters are obtained, including the hole axis inclination angle, which comes from the spatial attitude data of the holes in the hole group arrangement; the base material wall thickness, which comes from the manufacturing limit parameters and the wall thickness analysis results of the flow channel shell model; the hole radius, which is taken from the hole size parameters of the hole group arrangement; the shallow cavity volume, which is obtained through the volume measurement function of the 3D model of the circumferential shallow cavity connectivity scheme; and the lining surface area, which is the lining surface area of ​​the priority arrangement area. The wall area and angular frequency are calculated based on the acoustic analysis frequency range in the operating parameters. The angular frequency is the product of the frequency and twice pi. The gas density, sound velocity, and dynamic viscosity are taken from the operating parameter set. To calculate the equivalent thickness of the hole, the base material wall thickness is first geometrically stretched according to the hole axis inclination angle. The length after stretching is the base material wall thickness divided by the cosine of the hole axis inclination angle. Then, the end correction values ​​at both ends of the hole are superimposed. The end correction values ​​are empirically determined based on the flow characteristics of the orifice, usually 1.6 times the hole radius, that is, 0.8 times the hole radius is corrected at each end of the hole. The length after stretching is added to the end correction values ​​to obtain the equivalent thickness of the hole.

[0032] The pore impedance is calculated based on the Maa approximation and in combination with equivalent thickness, porosity, pore radius, dynamic viscosity, gas density, and angular frequency. Specifically, the Maa approximation model is used to describe the acoustic impedance characteristics of the aperture. The aperture impedance is in complex form, containing the real part corresponding to viscous loss and the imaginary part corresponding to inertial effects. The formula for calculating the aperture impedance is:

[0033] In the formula, Represents the position of the centerline arc length The acoustic impedance of the aperture at angular frequency ω reflects the aperture's ability to impede the propagation of sound waves. The dynamic viscosity of the gas. Let be the equivalent thickness of the hole at position s along the centerline arc length. For open area ratio, Where is the radius of the hole. Angular frequency, For gas density, The imaginary unit; Corresponding energy loss, Corresponding phase change.

[0034] The volume of the back cavity per unit area is obtained by the ratio of the shallow cavity volume to the lining surface area. Calculate the shallow cavity capacitive reactance based on gas density, sound velocity, angular frequency, and back cavity volume per unit area; Specifically, the volume of the shallow cavity is divided by the surface area of ​​the lining to obtain the volume of the back cavity per unit area. This value reflects the size of the shallow cavity volume corresponding to a unit lining area. The acoustic response characteristics of the circumferential shallow cavity are described using acoustic capacitance theory. The formula for calculating the capacitance of the shallow cavity is as follows:

[0035] In the formula, Position of the centerline arc length angular frequency The acoustic impedance of the lower aperture reflects the shallow cavity's ability to store acoustic energy; The imaginary unit, For gas density, The speed of sound in a gas. Angular frequency, Position of the centerline arc length The volume of the back cavity per unit area at that location.

[0036] The equivalent surface complex impedance is obtained by superimposing the aperture impedance and shallow cavity capacitive reactance at the same centerline arc length and the same angular frequency. Specifically, the aperture impedance and shallow cavity capacitive reactance are matched with the same centerline arc length and the same angular frequency to form corresponding impedance and capacitive reactance data pairs. Complex superposition operation is performed on each set of matched data. According to the principle of acoustic impedance series superposition, the real part of the equivalent surface complex impedance is the real part of the aperture impedance, and the imaginary part is the algebraic sum of the imaginary parts of the aperture impedance and the imaginary parts of the shallow cavity capacitive reactance, thus obtaining the corresponding equivalent surface complex impedance value.

[0037] The performance index calculation and correlation module is used to calculate the system insertion loss based on the equivalent surface complex impedance, calculate the system additional pressure drop based on the single-hole volumetric flow rate, combine the system insertion loss and the system additional pressure drop into index pairs and correlate them with their corresponding design variable sets. In embodiments of the present invention, the system insertion loss is calculated based on the equivalent surface complex impedance, and the system additional pressure drop is calculated based on the single-orifice volumetric flow rate. The system insertion loss and system additional pressure drop are combined into an index pair and associated with their corresponding set of design variables, including: Dividing the equivalent surface complex impedance by the product of the gas density and the sound velocity yields the dimensionless impedance. The absorption coefficient is obtained by calculating the normal incident absorption coefficient of the dimensionless impedance; Specifically, the equivalent surface complex impedance is matched with the gas density and sound velocity corresponding to the same centerline arc length position and angular frequency. The dimensionless impedance is obtained by using the equivalent surface complex impedance as the dividend and the product of the gas density and sound velocity as the divisor. The complex division rule is that the real and imaginary parts are divided by the product of the gas density and sound velocity, respectively. The dimensionless impedance reflects the relative magnitude and phase characteristics of the impedance. The normal incident absorption coefficient is then calculated from the dimensionless impedance using the following formula:

[0038] In the formula, Position of the centerline arc length angular frequency The sound absorption coefficient is below. This represents the real part of the dimensionless impedance. This is the imaginary part of the dimensionless impedance.

[0039] The sound absorption coefficient is obtained by wideband arithmetic mean. The average sound absorption coefficient is then calculated by inserting the average sound absorption coefficient and weighted and summed with the center line arc length to obtain the system insertion loss. Specifically, based on the frequency range of acoustic interest, the broadband analysis range is determined to be from 20Hz to 20000Hz. This range is divided into multiple sub-bands with equal frequency intervals of 200Hz. Each sub-band corresponds to a unique angular frequency. For each centerline arc length position, the absorption coefficients of all sub-bands within the broadband are extracted. The average absorption coefficient at this position is calculated using the arithmetic mean method. Then, based on the correlation formula between insertion loss and average absorption coefficient, the insertion loss at each arc length position is calculated using the formula: [Formula omitted for brevity].

[0040] In the formula, Position of the centerline arc length Insertion loss at that point, Position of the centerline arc length The average sound absorption coefficient at that location; the formula is based on the relationship between the sound absorption coefficient and the sound energy attenuation, reflecting the ability of that location to weaken sound waves.

[0041] In detail, the arc length range is divided into multiple small arc segments along the centerline of the flow channel. The length of each arc segment does not exceed one-tenth of the flow channel diameter. The weight of each arc segment is its actual length. The insertion loss corresponding to each arc segment is multiplied by the weight to obtain the weighted insertion loss of that arc segment. The weighted insertion losses of all arc segments are accumulated to obtain the overall system insertion loss of the flow channel.

[0042] The orifice area is calculated based on the orifice radius. The gas flow rate of the orifice is obtained by dividing the volumetric flow rate of a single orifice by the orifice area. Based on the gas flow rate and gas density, the local additional pressure drop of each orifice is obtained. The additional pressure drop of the system is obtained by superimposing the local additional pressure drops of all the holes; Specifically, the cross-sectional area of ​​a single hole is obtained by calculating the area of ​​the hole using the formula for the area of ​​a circle. The volumetric flow rate of the single hole is divided by the cross-sectional area of ​​the corresponding hole to calculate the gas velocity of the hole. The product of the square of the gas velocity and the local resistance coefficient is multiplied by 0.5 times the gas density to obtain the local additional pressure drop of the single hole. The local resistance coefficient is determined according to the manufacturing process. The local additional pressure drops of all holes are superimposed, and the system additional pressure drop is obtained by algebraically summing the local additional pressure drops of all single holes.

[0043] The system insertion loss and system additional pressure drop are combined into a performance index pair, and their corresponding hole axis tilt angle, opening ratio, back cavity volume per unit area, circumferential shallow cavity connectivity scheme and hole group arrangement are associated. Specifically, the system insertion loss and system additional pressure drop are formed into ordered performance index pairs in the form of (system insertion loss value, system additional pressure drop value). Each performance index pair is marked with the corresponding calculation condition parameters. The performance index pair is used as the core key value and associated with the corresponding hole axis inclination angle, opening ratio, back cavity volume per unit area, circumferential shallow cavity connection scheme identifier, and hole group arrangement identifier.

[0044] The multi-objective trade-off and solution verification module is used to form a trade-off curve on the index pair plane of system additional voltage drop and system insertion loss, and to use the curvature maxima of the geometric inflection point of the trade-off curve as candidate solutions, and to perform consistency verification on the candidate solutions to obtain the definite solution; In an embodiment of the present invention, a tradeoff curve is formed on the index pair plane of system additional voltage drop and system insertion loss. The curvature maxima of the geometric inflection point of the tradeoff curve are used as candidate solutions. Consistency checks are performed on the candidate solutions to obtain a definitive solution, including: Plot index points with the system additional voltage drop as the horizontal axis and the system insertion loss as the vertical axis, and filter the index points: retain index points that do not have another index pair that satisfy both a smaller system additional voltage drop and a larger system insertion loss; Specifically, extract all numerical pairs of system additional voltage drop and system insertion loss, along with their corresponding indicator point labels. Remove abnormal indicator points where the system additional voltage drop or system insertion loss is negative. Using system additional voltage drop as the horizontal axis and system insertion loss as the vertical axis, determine the coordinate axis scale range based on the numerical range of the effective indicator points, and plot the indicator points in the coordinate system. Evaluate all effective indicator points using a point-by-point comparison method. For each indicator point to be evaluated, iterate through all other indicator points. If an indicator point exists that satisfies both a smaller system additional voltage drop and a larger system insertion loss, then the indicator point to be evaluated is determined to be non-optimal and marked for removal. If no such indicator point exists after iteration, then the indicator point to be evaluated is determined to be optimal and retained.

[0045] The retained indicators are sorted in ascending order of system additional pressure drop, and a continuous trade-off curve is obtained by cubic spline fitting. The geometric inflection point of each point is obtained based on the discrete curvature of three adjacent points, and the point with the maximum curvature is taken as a candidate solution. Specifically, the retained index pairs are sorted in ascending order of system additional pressure drop. The sorted system additional pressure drop is used as the independent variable on the horizontal axis, and the corresponding system insertion loss is used as the dependent variable on the vertical axis. A continuous tradeoff curve is constructed using cubic spline fitting, ensuring the curve satisfies the continuity of the first and second derivatives. Along the sorted index pair sequence, calculation units are constructed by grouping three adjacent points. For each group of three points, the discrete curvature formula is applied to their coordinate values ​​(system additional pressure drop, system insertion loss). The formula first calculates the center and radius of the circle formed by the three points, then takes the reciprocal of the radius as the discrete curvature of the intermediate point of the group. The curvature value of each intermediate index pair is calculated sequentially. For the first and last index pairs of the sequence, a three-point group is constructed by supplementing the adjacent two points and the nearby points on the fitted curve to calculate the curvature. By comparing the curvature change trend of adjacent index pairs, if the curvature value before and after a certain point shows a change of first increasing and then decreasing or first decreasing and then increasing, it is determined to be a geometric inflection point. The curvature values ​​of all inflection points are compared, and the inflection point with the largest curvature value is selected as the candidate solution.

[0046] The circumferential static pressure difference corresponding to the candidate solution is used to back-calculate the single-hole volumetric flow rate of each section to check the zero net mass exchange constraint. At the same time, the equivalent surface complex impedance, insertion loss and additional pressure drop are recalculated for the design variable set associated with the candidate solution. If they are inconsistent with the inflection point index, the hole axis inclination angle, opening ratio, back cavity volume per unit area or hole pairing relationship are adjusted locally in the corresponding section and the check is repeated until the inflection point index is met and the definite solution is obtained. Specifically, the circumferential static pressure difference distribution data and design variable set corresponding to the candidate solutions are retrieved: orifice axis inclination angle, opening ratio, unit area back cavity volume, orifice pairing relationship, and inflection point indicators: system insertion loss and system additional pressure drop. The circumferential static pressure difference is matched with the position of each cross-section of the flow channel, and the volumetric flow rate of all orifices in each cross-section is recalculated. Zero net mass exchange constraint verification is performed on each cross-section. If a cross-section does not meet the zero net mass exchange constraint, it is marked as an area to be adjusted. Based on the design variable set of the candidate solutions, the equivalent surface complex impedance, system insertion loss, and system additional pressure drop are recalculated. The recalculated results are compared with the inflection point indicators. If the insertion loss deviation exceeds 0.5 dB or the additional pressure drop deviation exceeds 50 Pascal, it is judged as inconsistent and needs to be adjusted. During adjustment, the focus is on the cross-section to be adjusted and the area of ​​indicator deviation. First, adjust the hole axis tilt angle, within ±5 degrees of the original tilt angle, ensuring it does not exceed the manufacturing limit. If the indicators are still inconsistent after adjustment, adjust the opening ratio, with the increase or decrease not exceeding 10% of the original opening ratio, or adjust the back cavity volume per unit area by changing the shallow cavity depth, with the adjustment not exceeding 15% of the original volume. If necessary, re-pair the holes in the cross section, keeping the direction from the high-pressure side to the low-pressure side unchanged, and optimize the absolute value deviation of the flow rate of the paired holes to within 5%. After each adjustment, repeat the single-hole volumetric flow rate calculation, zero net mass exchange constraint check, and recalculation of the equivalent surface complex impedance insertion loss and additional pressure drop until all cross sections meet the zero net mass exchange constraint and the deviation of the recalculated indicators from the inflection point indicators is within the allowable range. Output the design variable set and the corresponding structural parameters as the definitive solution.

[0047] The design and manufacturing output module is used to take the deterministic solution as parametric computer-aided design data and formulate manufacturing points. In embodiments of the present invention, determining the solution as parameterized computer-aided design data and formulating manufacturing points includes: The design parameters in the determined solution are associated with the three-dimensional model of the flow channel shell to generate a fully parametric three-dimensional CAD model; Based on the characteristics of additive manufacturing processes and the geometric features of deterministic solutions, key manufacturing points are given, including: build direction, support and powder removal channels, and inaccessible areas; Specifically, the design parameter set from the determined solution is retrieved, including hole axis inclination angle, opening ratio, hole radius, shallow cavity depth, hole group arrangement coordinates, circumferential connecting channel dimensions, etc., as well as the basic 3D model of the flow channel shell. The parametric modeling module of the CAD software is used to establish a mapping between the design parameters and model features. The hole radius is associated with the diameter parameter of the hole feature, the shallow cavity depth with the stretching depth parameter of the shallow cavity feature, the hole group arrangement coordinates with the positioning parameters of the hole feature, and the circumferential connecting channel dimensions with the cross-sectional parameters of the channel feature, forming a parameter-driven relationship chain. Then, parameter variable ranges are set, with the upper and lower limits of each parameter not exceeding manufacturing limits. The model regeneration function is enabled to verify the parameter correlation, and any parameter is modified... The model features should be automatically updated without geometric conflicts, generating a fully parametric 3D CAD model. Geometric features, including hole aspect ratio, shallow cavity overhang angle, and hole density, are extracted based on additive manufacturing process characteristics to determine the construction direction. Using the flow channel centerline as a reference, the process adaptability of different directions, such as axial along the centerline, radial perpendicular to the centerline, and at a 45-degree angle to the centerline, is compared. The direction with an angle of no less than 30 degrees between the hole axis and the construction direction is prioritized to reduce hole forming deviation and a shallow cavity overhang angle of no more than 45 degrees, thus lowering support requirements. If multiple options exist, forming accuracy and material utilization are evaluated using process simulation software to select the optimal direction. Support design is then performed. Support and Powder Cleaning Channels: For the overhanging structure at the bottom of shallow cavities with an overhang length exceeding 2 mm, add removable supports using a mesh structure. The support density increases with the overhang length. A 0.5 mm thick easy-peel layer is applied to the connection surface between the support and the base material. For circumferential shallow cavities and closed cavities formed by hole groups with a volume exceeding 5 cubic centimeters, powder cleaning channels are radially installed at both ends of the cavity along the flow path. The channel diameter is not less than 8 mm to ensure that powder cleaning tools can be inserted. The radius of the corner at the connection between the channel and the cavity is not less than 1 mm to avoid stress concentration. Identifying Inaccessible Areas: Use the spatial analysis function of CAD software to check for areas inside the hole groups and at the corners of shallow cavities that have a diameter less than 3 mm and a depth exceeding 10 mm. For blind holes of millimeters, lasers are difficult to focus during additive manufacturing, or for narrow gaps with angles less than 30 degrees, powder is difficult to spread. For these inaccessible areas, the distribution density of holes is adjusted, the spacing between adjacent holes is increased to more than 5 millimeters, or the corners of shallow cavities are modified to rounded corners with a radius of not less than 2 millimeters. If necessary, the hole depth is locally reduced to ensure that the depth-to-diameter ratio does not exceed 5. The accessibility of the modified areas is verified through process simulation. Finally, the key manufacturing points are integrated to form a process guidance document, which includes a 3D schematic diagram of the construction direction, the position and size parameters of the support and powder cleaning channels, and a comparison of the modified and unmodified areas. This document is stored in association with the fully parametric 3D CAD model, and a dataset that can be directly used for additive manufacturing is output.

[0048] To address the aforementioned problems, this invention also provides an intelligent design method for complex flow channel housing parts with porous systems used in aerospace applications, the method comprising: S1. Obtain the three-dimensional flow channel shell model, working condition parameter set, and manufacturing limits; S2. Extract the centerline arc length from the three-dimensional flow channel shell model and determine the radius of curvature distribution. Generate candidate arrangement zones based on the inner curved wall and the post-bend expansion section of the three-dimensional flow channel shell model. S3. Within the candidate arrangement zone, determine the circumferential static pressure difference along the arc length of the centerline based on the curvature radius distribution and the set of working parameters, and select the priority arrangement area based on the circumferential static pressure difference. S4. Construct circumferentially connected shallow cavities within the priority arrangement area, group the holes in the circumferentially connected shallow cavities, determine the single-hole volumetric flow rate of each hole based on the circumferential static pressure difference, and generate the circumferentially connected shallow cavity scheme and hole group arrangement based on the single-hole volumetric flow rate. S5. Based on the circumferential shallow cavity connection scheme and the arrangement of the hole group, calculate the hole impedance and shallow cavity capacitive reactance, and combine the hole impedance and shallow cavity capacitive reactance into an equivalent surface complex impedance. S6. Calculate the system insertion loss based on the equivalent surface complex impedance, calculate the system additional pressure drop based on the single-hole volumetric flow rate, combine the system insertion loss and the system additional pressure drop into an index pair and associate them with their corresponding set of design variables. S7. Form a trade-off curve on the index pair plane of system additional pressure drop and system insertion loss, and take the curvature maxima of the geometric inflection point of the trade-off curve as the candidate solution. Perform consistency check on the candidate solutions to obtain the definite solution. S8. Use the determined solution as parametric computer-aided design data and formulate manufacturing points.

[0049] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An intelligent design system for complex flow channel shell parts with porous systems for airborne applications, characterized in that, include: The data acquisition module is used to acquire the three-dimensional flow channel shell model, working condition parameter set, and manufacturing limits; The feature extraction and layout strip generation module is used to extract the centerline arc length and determine the radius of curvature distribution from the three-dimensional flow channel shell model, and generate candidate layout strips based on the inner curved wall and the post-bend expansion section of the three-dimensional flow channel shell model. The static pressure analysis and priority area screening module is used to determine the circumferential static pressure difference along the centerline arc length within the candidate layout zone based on the curvature radius distribution and the set of working parameters, and to screen out the priority layout zone based on the circumferential static pressure difference. The orifice group design and optimization module is used to construct circumferentially connected shallow cavities in the priority arrangement area, group the orifices in the circumferentially connected shallow cavities, determine the single-orifice volumetric flow rate of each orifice based on the circumferential static pressure difference, and generate the circumferential shallow cavity connection scheme and orifice group arrangement based on the single-orifice volumetric flow rate. The acoustic impedance synthesis module is used to calculate the aperture impedance and shallow cavity capacitive reactance based on the circumferential shallow cavity connectivity scheme and aperture group arrangement, and synthesize the aperture impedance and shallow cavity capacitive reactance into an equivalent surface complex impedance. The performance index calculation and correlation module is used to calculate the system insertion loss based on the equivalent surface complex impedance, calculate the system additional pressure drop based on the single-hole volumetric flow rate, combine the system insertion loss and the system additional pressure drop into index pairs and correlate them with their corresponding design variable sets. The multi-objective trade-off and solution verification module is used to form a trade-off curve on the index pair plane of system additional voltage drop and system insertion loss, and to use the curvature maxima of the geometric inflection point of the trade-off curve as candidate solutions, and to perform consistency verification on the candidate solutions to obtain the definite solution; The design and manufacturing output module is used to take the determined solution as parametric computer-aided design data and formulate manufacturing points.

2. The intelligent design system for complex flow channel shell parts with porous systems for airborne applications according to claim 1, characterized in that, Obtain the 3D flow channel shell model, operating parameter set, and manufacturing limits, including: The three-dimensional flow channel shell model, operating parameter set, and manufacturing limits are obtained. The operating parameter set includes gas density, dynamic viscosity, near-wall representative velocity, and sound velocity. The manufacturing limits include the range of hole radius and the range of base material wall thickness. The coordinates and units of the three-dimensional flow channel shell model are then unified.

3. The intelligent design system for complex flow channel shell parts with porous systems for airborne applications according to claim 2, characterized in that, The centerline arc length is extracted from the 3D flow channel shell model, and the radius of curvature distribution is determined. Candidate arrangement zones are generated based on the inner curved wall and the post-bend diffuser section of the 3D flow channel shell model, including: The centerline of the inner cavity is extracted from the three-dimensional flow channel shell model, and the arc length is obtained by spline fitting and parameterization according to the arc length. The curvature of the centerline arc length is calculated based on equidistant sampling to obtain the curvature radius distribution; Establish a local orthogonal system at each sampling section to determine the inner curved wall, and record the radius difference between the inner and outer curves to the center line; Under the condition of meeting the manufacturing limit, a strip-shaped region is formed by expanding the inner wall of the bend, and a strip-shaped region is added as a post-bend gradual expansion section in the section where the cross-sectional area increases gradually after the bend. The intersection of the inner curved wall strip and the post-bend widening section is considered as a candidate layout zone.

4. The intelligent design system for complex flow channel shell parts with porous systems for airborne applications according to claim 3, characterized in that, Within the candidate arrangement zone, the circumferential static pressure difference along the centerline arc length is determined based on the curvature radius distribution and the set of operating parameters. Preferred arrangement areas are then selected based on this circumferential static pressure difference, including: Within the candidate arrangement zone, the circumferential static pressure difference is approximately calculated by centrifugal equilibrium based on the curvature radius distribution, near-wall representative velocity, gas density, and the difference in the inner and outer bending radii of the cross section along the arc length of the centerline. The priority layout area is obtained by taking the local maximum value of the circumferential static pressure difference as the center and the adjacent local minimum values ​​as the interval boundary.

5. The intelligent design system for complex flow channel shell parts with porous systems for airborne applications according to claim 4, characterized in that, Within the priority layout area, construct circumferentially connected shallow cavities. Group the orifices within these circumferentially connected shallow cavities. Determine the single-orifice volumetric flow rate of each orifice based on the circumferential static pressure difference. Generate a circumferentially connected shallow cavity scheme and orifice group layout based on the single-orifice volumetric flow rate, including: Within the priority layout area, a continuous circumferential shallow cavity ring is constructed along the circumference of the flow channel according to manufacturing limits; Based on the high-pressure side and low-pressure side of the circumferential static pressure difference, the holes are arranged in groups from the high-pressure side to the low-pressure side. Calculate the volumetric flow rate of a single orifice based on orifice radius, orifice flow coefficient and circumferential static pressure difference; By applying zero net mass exchange constraints to each cross section of the flow channel inside the shell, and by adjusting the number of holes and the pairing method of the holes, the algebraic sum of the volumetric flow rate of a single hole in the cross section is made zero, thus obtaining the circumferential shallow cavity connection scheme and hole group arrangement.

6. The intelligent design system for complex flow channel shell parts with porous systems for airborne applications according to claim 1, characterized in that, Based on the circumferential shallow cavity connectivity scheme and the arrangement of the hole group, the hole impedance and shallow cavity capacitive reactance are calculated, and the hole impedance and shallow cavity capacitive reactance are combined into an equivalent surface complex impedance, including: Based on the circumferential shallow cavity connection scheme and the hole group arrangement, the opening ratio was statistically analyzed, and the hole axis inclination angle, base material wall thickness, hole radius, shallow cavity volume, lining surface area, angular frequency, gas density, sound velocity and dynamic viscosity were obtained. The base material wall thickness is geometrically stretched according to the hole axis inclination angle, and the end corrections at both ends of the hole are superimposed to obtain the equivalent thickness of the hole; The pore impedance is calculated based on the Maa approximation and in combination with equivalent thickness, porosity, pore radius, dynamic viscosity, gas density, and angular frequency. The volume of the back cavity per unit area is obtained by the ratio of the shallow cavity volume to the lining surface area. Calculate the shallow cavity capacitive reactance based on gas density, sound velocity, angular frequency, and back cavity volume per unit area; The equivalent surface complex impedance is obtained by superimposing the aperture impedance and shallow cavity capacitive reactance at the same centerline arc length and the same angular frequency.

7. The intelligent design system for complex flow channel shell parts with porous systems for airborne applications according to claim 6, characterized in that, The system insertion loss is calculated based on the equivalent surface complex impedance, and the system additional pressure drop is calculated based on the single-orifice volumetric flow rate. The system insertion loss and system additional pressure drop are combined into an index pair and associated with their corresponding set of design variables, including: Dividing the equivalent surface complex impedance by the product of the gas density and the sound velocity yields the dimensionless impedance. The absorption coefficient is obtained by calculating the normal incident absorption coefficient of the dimensionless impedance; The sound absorption coefficient is obtained by wideband arithmetic mean. The average sound absorption coefficient is then calculated by inserting the average sound absorption coefficient and weighted and summed with the center line arc length to obtain the system insertion loss. The orifice area is calculated based on the orifice radius. The gas flow rate of the orifice is obtained by dividing the volumetric flow rate of a single orifice by the orifice area. Based on the gas flow rate and gas density, the local additional pressure drop of each orifice is obtained. The additional pressure drop of the system is obtained by superimposing the local additional pressure drops of all the holes; The system insertion loss and system additional pressure drop are combined into a performance index pair, and their corresponding hole axis tilt angle, opening ratio, back cavity volume per unit area, circumferential shallow cavity connectivity scheme and hole group arrangement are associated.

8. The intelligent design system for complex flow channel shell parts with porous systems for airborne applications according to claim 7, characterized in that, A tradeoff curve is formed on the index pair plane of system additional pressure drop and system insertion loss. The curvature maxima of the geometric inflection point of the tradeoff curve are used as candidate solutions. The consistency of the candidate solutions is checked to obtain the definite solutions, including: Plot index points with the system additional voltage drop as the horizontal axis and the system insertion loss as the vertical axis, and filter the index points: retain index points that do not have another index pair that satisfy both a smaller system additional voltage drop and a larger system insertion loss; The retained indicators are sorted in ascending order of system additional pressure drop, and a continuous trade-off curve is obtained by cubic spline fitting. The geometric inflection point of each point is obtained based on the discrete curvature of three adjacent points, and the point with the maximum curvature is taken as a candidate solution. The circumferential static pressure difference corresponding to the candidate solution is used to back-calculate the single-hole volumetric flow rate of each section to verify the zero net mass exchange constraint. At the same time, the equivalent surface complex impedance, insertion loss and additional pressure drop are recalculated for the design variable set associated with the candidate solution. If they are inconsistent with the inflection point index, the hole axis inclination angle, opening ratio, back cavity volume per unit area or hole pairing relationship are adjusted locally in the corresponding section and the verification is repeated until the inflection point index is met to obtain the definite solution.

9. The intelligent design system for complex flow channel shell parts with porous systems for airborne applications according to claim 1, characterized in that, The determined solution is used as parametric computer-aided design data and manufacturing considerations are established, including: The design parameters in the determined solution are associated with the three-dimensional model of the flow channel shell to generate a fully parametric three-dimensional CAD model; Based on the characteristics of additive manufacturing processes and the geometric features of deterministic solutions, key manufacturing points are given, including: build direction, support and powder removal channels, and inaccessible areas.

10. A smart design method for complex flow channel shell parts with porous systems for airborne applications, characterized in that, The method includes: S1. Obtain the three-dimensional flow channel shell model, working condition parameter set, and manufacturing limits; S2. Extract the centerline arc length from the three-dimensional flow channel shell model and determine the radius of curvature distribution. Generate candidate arrangement zones based on the inner curved wall and the post-bend expansion section of the three-dimensional flow channel shell model. S3. Within the candidate arrangement zone, determine the circumferential static pressure difference along the arc length of the centerline based on the curvature radius distribution and the set of working parameters, and select the priority arrangement area based on the circumferential static pressure difference. S4. Construct circumferentially connected shallow cavities within the priority arrangement area, group the holes in the circumferentially connected shallow cavities, determine the single-hole volumetric flow rate of each hole based on the circumferential static pressure difference, and generate the circumferentially connected shallow cavity scheme and hole group arrangement based on the single-hole volumetric flow rate. S5. Based on the circumferential shallow cavity connection scheme and the arrangement of the hole group, calculate the hole impedance and shallow cavity capacitive reactance, and combine the hole impedance and shallow cavity capacitive reactance into an equivalent surface complex impedance. S6. Calculate the system insertion loss based on the equivalent surface complex impedance, calculate the system additional pressure drop based on the single-hole volumetric flow rate, combine the system insertion loss and the system additional pressure drop into an index pair and associate them with their corresponding set of design variables. S7. Form a trade-off curve on the index pair plane of system additional pressure drop and system insertion loss, and take the curvature maxima of the geometric inflection point of the trade-off curve as the candidate solution. Perform consistency check on the candidate solutions to obtain the definite solution. S8. Use the determined solution as parametric computer-aided design data and formulate manufacturing points.

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