A method for parametric design of an aeroengine fluidic oscillator and the resulting fluidic oscillator

Abstract

The application discloses a parameterized design method of an aero-engine fluid oscillator, and comprises the following steps: establishing an XY coordinate system and defining a reference parameter L0; determining key geometric parameters on a flow passage profile through a proportional correlation function based on the reference parameter L0; sequentially calculating coordinates of each key node on a left half profile of the fluid oscillator according to the key geometric parameters of each region and combining geometric constraint relationships; connecting each key node through straight line segments and circular arc segments in sequence, ensuring that tangent continuity conditions are met at connecting points between segments, so as to form a left half profile curve of the fluid oscillator; mirroring the left half profile curve about the y-axis to obtain a complete two-dimensional geometric profile of the fluid oscillator; and finally, performing spanwise stretching to obtain a complete three-dimensional geometric profile of the fluid oscillator. The application establishes a full-parameter correlation system with a core reference parameter as a reference, and through changing the reference parameter and the proportional correlation coefficient, the parameterized design of the fluid oscillator can be more flexible and faster.

Description

Technical Field

[0001] This invention relates to the field of airflow control technology for aero-engine inlets, and specifically to a parametric design method for an aero-engine fluid oscillator and the resulting fluid oscillator. Background Technology

[0002] Air-breathing propulsion systems are the core components of aircraft operating within the atmosphere. The air intake is a crucial part of these systems, responsible for capturing incoming airflow for downstream components such as the compressor and combustion chamber, and decelerating and pressurizing the air to a suitable speed. As aircraft operate at increasingly higher Mach numbers, even entering the hypersonic realm (Mach numbers greater than 5), numerous unfavorable flows closely related to shock wave / boundary layer interference exist within the air intake, severely impacting its performance. Besides the trend towards higher speeds, some air intakes employ highly curved "serpentine" ducts, relying on their own shape to obstruct the view of the intake outlet. In such scenarios, the drastic curvature changes within the air intake induce separated and distorted flows, resulting in a highly non-uniform flow field that affects the proper matching between the air intake and the compressor. Therefore, existing technologies propose various flow control methods to improve the flow field quality within the air intake, including:

[0003] 1. The vortex generator generates flow vortices by installing small vanes on the wall, thereby enhancing the mixing between the mainstream and the fluid near the wall. This method has a simple structure, but it is a fixed device and the control effect cannot be adjusted according to changes in operating conditions.

[0004] 2. Steady blowing / suction method. This method improves the flow state by injecting or extracting airflow into the flow field through blowing or suction holes set on the wall of the air inlet. However, this method requires a continuous high-pressure air source or negative pressure source, resulting in high energy consumption and the need for an additional piping system.

[0005] 3. Zero-mass synthetic jet technology. This method involves setting up a cavity at a controlled location, within which a periodic jet is generated using the vibration of a thin film or the reciprocating motion of a piston, without the need for an external gas supply. However, this method often struggles to achieve a satisfactory trade-off between the range of motion / excitation intensity of the movable parts and the complexity / volume of the additional cavity.

[0006] In contrast, a fluid oscillator, as a geometrically fixed fluid device, can generate a self-sustaining, reciprocating swept jet under a fixed pressure differential, thereby achieving flow control. For example... Figure 1As shown, the internal flow channel of the existing fluid oscillator has a symmetrical bifurcated structure, mainly including an inlet section, an inner conductor, a mixing chamber, a feedback channel, an outlet throat, and an outlet section. When the high-pressure gas source enters the mixing chamber from the inlet, the inner conductor on one side generates the Coanda effect (or Coanda effect) on the airflow, guiding the airflow to adhere to the wall on that side. On the inner conductor on the other side where the airflow does not adhere, a recirculation zone is formed. Then, the airflow on the adhered side splits into two. Part of the airflow flows back to the upstream of the mixing chamber near the inlet along the feedback channel on the same side, while the other part flows out from the throat. The airflow flowing back to the upstream of the mixing chamber near the inlet along the feedback channel interacts with the fresh airflow flowing in from outside the oscillator, causing the main stream to move to the inner conductor on the other side and adhere. This process repeats repeatedly, eventually generating a periodic sweeping oscillating jet at the outlet section.

[0007] As can be seen, the internal structure of a fluid oscillator is quite complex. Besides the numerous curves requiring design along the inlet, mixing, and outlet sections of the central axis, the inner conductor also has an irregular shape, composed of various straight lines and curves, and exhibits significant positional freedom in the four directions (up, down, left, and right). Poor design of the fluid oscillator can easily lead to the oscillation amplitude and frequency failing to meet expectations, or even prevent successful oscillation altogether. Furthermore, in practical engineering, the design efficiency of fluid oscillators is crucial. In situations where computational fluid dynamics or experimental methods are needed to verify the performance of fluid oscillators, a parametric design method for designing fluid oscillators is urgently required. Summary of the Invention

[0008] Purpose of the invention: This invention provides a parametric design method for aero-engine fluid oscillators, which can design the two-dimensional surface of the fluid oscillator according to a clear geometric meaning, and the new geometric surface can be updated and adjusted in a timely manner after the design parameters are changed.

[0009] The present invention also provides a fluid oscillator obtained by using the parametric design method of the aero-engine fluid oscillator.

[0010] Technical Solution: The parametric design method for aero-engine fluid oscillators provided by this invention adopts the following technical solution:

[0011] A parametric design method for aero-engine fluid oscillators includes the following steps:

[0012] S1. Taking the center point of the fluid oscillator outlet as the origin O(0,0), the y-axis along the axis of symmetry of the fluid oscillator and the x-axis in the horizontal direction, determine the key node O1 in the outlet throat region, and define the horizontal distance from the key node O1 to the origin as the half-width distance L0 of the outlet throat.

[0013] S2. Calculate the key geometric parameters of each region based on the half-width distance L0 of the throat in the exit section;

[0014] S3. Based on the key geometric parameters of each region mentioned above, and in conjunction with the geometric constraints, calculate the coordinates of each key node.

[0015] S4. Connect the key nodes according to the preset connection rules to form the flow channel profile curve of the left half of the fluid oscillator.

[0016] S5. Mirror the left half of the surface curve about the y-axis to obtain the complete two-dimensional geometry of the fluid oscillator. Then, stretch the surface to obtain the complete three-dimensional geometry of the fluid oscillator.

[0017] Furthermore, step S2 includes the following parameters: outlet half-width L1, radius of the large arc on the upper wall of the mixing chamber L2, half-width of the mixing chamber L3, radius of the arc on the upper wall of the feedback channel L5, lateral distance from the outer wall of the feedback channel to the y-axis L6, height of the vertical section of the feedback channel L7, radius of the arc at the bottom of the feedback channel L8, width of the feedback channel L9, and vertical height of the inner conductor section L. 10 Top arc radius L 11 The vertical height of the left side region of the inner conductor is L. 12 The radius L of the bottom left arc of the inner conductor 13 The horizontal distance L from the bottom right point of the inner conductor to the y-axis 14 Vertical height L of the right side region of the inner conductor 15 The radius L of the right arc of the inner conductor 16 The minimum lateral distance L from the y-axis to the contraction zone of the inlet section 17 The maximum lateral distance L from the y-axis to the contraction zone of the inlet section 18 Vertical height L of the inlet straight pipe section 19 .

[0018] Furthermore, in S2, based on the reference parameter L0, the key geometric parameters on the flow channel profile are determined through a proportional correlation function, which is as follows: L x =α x ×L0, where α x This is the proportional correlation coefficient.

[0019] Furthermore, in S2, the exit half-width L1 = α1 × L0;

[0020] The radius of the large circular arc on the upper wall of the mixing cavity is L2 = α2 × L0;

[0021] The half-width of the mixing cavity L3 = α3 × L0;

[0022] The radius of the rounding in the mixing cavity region is L4 = α4 × L0;

[0023] The radius of the arc on the upper wall of the feedback channel is L5 = α5 × L0;

[0024] The lateral distance from the outer wall of the feedback channel to the y-axis is L6 = α6 × L0 = 5 × 0.75;

[0025] The vertical section height of the feedback channel is L7 = α7 × L0;

[0026] The radius of the bottom arc of the feedback channel is L8 = α8 × L0;

[0027] The feedback channel width is L9 = α9 × L0;

[0028] The vertical height of the inner conductor segment is L 10 =α 10 ×L0;

[0029] Top arc radius L 11 =α 11 ×L0;

[0030] Vertical height L of the left side region of the inner conductor 12 =α 12 ×L0;

[0031] Radius L of the bottom left arc of the inner conductor 13 =α 13 ×L0;

[0032] The horizontal distance L from the bottom right point of the inner conductor to the y-axis 14 =α 14 ×L0;

[0033] The vertical height of the region on the right side of the inner conductor is L. 15 =α 15 ×L0;

[0034] Radius L of the right arc of the inner conductor 16 =α 16 ×L0;

[0035] The minimum lateral distance of the inlet segment contraction region from the y-axis is L. 17 =α 17 ×L0;

[0036] The maximum lateral distance of the inlet segment contraction region from the y-axis is L. 18 =α 18 ×L0;

[0037] The vertical height of the inlet straight pipe section is L 19 =α 19 ×L0;

[0038] Where α1 to α 19 This is the proportional correlation coefficient.

[0039] Furthermore, in step S3, the coordinates of each key node include:

[0040] The coordinates of point A at the edge of the exit section are (-L1, 0).

[0041] The coordinates of point O1 at the edge of the outlet throat segment are determined by the intersection of the extension of point A along the direction of angle θ1=40° and the point x=-L0.

[0042] The coordinates of the edge point B of the hybrid cavity segment are determined by the intersection of a circle with center O1 and radius L2 with the y-axis to obtain the key node O2, and then the intersection of a circle with center O2 and radius L2 with x=-L3 to determine the coordinates.

[0043] The coordinates of point C on the outer wall of the feedback channel are determined by the intersection of a circle with radius L5 and point B on the circumference with x=-L6, and the coordinates of the center point D of the circle are obtained from this intersection.

[0044] The coordinates of point E on the outer wall of the feedback channel are determined by the vertical distance L7 from the negative y-axis at point C.

[0045] The coordinates of point F on the lower wall of the feedback channel are determined by the endpoint of an arc with radius L8, starting point E, and tangent direction at point E as the vertical direction; this arc is designated as the first arc, and the tangent direction of the first arc at point F is horizontal.

[0046] Coordinates of the center point G of the first arc;

[0047] The coordinates of the vertex H in the contraction region of the entrance segment are: located at the positive x-axis of point F, with a horizontal distance L from the y-axis. 17 Sure;

[0048] The coordinates of vertex I in the contraction region of the entrance segment: Using the extension of the line from point H along the direction of angle θ3 = 12°, intersecting x = -L... 18 The intersection point is determined;

[0049] The coordinates of the lower vertex J of the inlet straight pipe section are: located vertically in the negative y-direction of the y-axis at point I, with a vertical distance of L. 19 Sure;

[0050] The coordinates of the top point K of the inner conductor are: located at the positive x-axis and positive y-axis of point E, with a horizontal distance of L9 and a vertical distance of L. 10 Sure;

[0051] The coordinates of the upper left wall of the inner conductor (L): The vertical distance from point K in the negative y-axis direction is L. 11 Sure;

[0052] Coordinates of point M on the lower left side of the inner conductor: This point is located in the negative vertical direction of the y-axis from point L, with a vertical distance of L. 12 Sure;

[0053] Coordinates of point N on the lower wall of the inner conductor: with radius L13 The starting point is point M, and the tangent direction at point M is vertical. The ending point of the arc is determined. This arc is set as the second arc, and the tangent direction of the second arc at point N is horizontal.

[0054] Coordinates of the center point P of the second arc;

[0055] Coordinates of point Q on the lower wall of the inner conductor: Located at the positive x-axis from point N, with a horizontal distance L from the y-axis. 14 Sure;

[0056] The coordinates of point R on the right side wall of the inner conductor are: a circle with center L and radius L. 11 The starting point is point K, and the tangent direction at point K is horizontal. The ending point of the arc is determined. This arc is set as the third arc, and the tangent direction of the third arc at point R is vertical.

[0057] Coordinates of point S on the right wall of the inner conductor: Located at the negative vertical direction of the y-axis from point R, with a vertical distance of L. 15 Sure;

[0058] The coordinates of point T on the right wall of the inner conductor: from radius L 16 The circle with the starting point being point S and the tangent at point S being in the vertical direction is defined by the intersection of the extension of the line from point Q along the direction of angle θ2=40°. The arc between point S and point T is the fourth arc.

[0059] The center point U of the fourth arc.

[0060] Furthermore, in S4, the connection rules include:

[0061] Connect the edge point A of the exit segment from the center point O along the negative x-axis with a straight line.

[0062] Connect the edge point A of the outlet section to the edge point O1 of the outlet throat section with a straight line, and perform a rounding treatment at point O1;

[0063] Connect the edge point O1 of the outlet throat section to the edge point B of the mixing cavity section with an arc of radius L2 and center point O2, and perform rounding treatment at point B;

[0064] Connect the edge point B of the mixing cavity section to the outer wall point C of the feedback channel with an arc of radius L5 and center point D;

[0065] Connect point C on the outer wall of the feedback channel to point E on the outer wall of the feedback channel in a straight line;

[0066] Connect point E on the outer wall of the feedback channel to point F on the lower wall of the feedback channel using an arc with radius L8 and center point G;

[0067] Connect point F to point H on the lower wall of the feedback channel in a straight line;

[0068] Connect point H to point I on the lower wall of the feedback channel with a straight line;

[0069] Connect point I to the entry segment point J by a straight line;

[0070] Connect point K at the top of the inner island to point L on the left outer wall of the inner island in a straight line;

[0071] Connect the point L on the outer left wall of the inner island to the point M on the lower wall of the inner island in a straight line.

[0072] Starting from point M on the lower wall of the inner island, with a radius of L... 13 An arc centered at point P connects to point N on the lower wall of the inner island.

[0073] Connect point N on the lower wall of the inner island to point Q on the lower wall of the inner island with a straight line;

[0074] Starting from the top point K of the inner island, with a radius of L 11 An arc centered at point L connects to point R on the outer wall of the right side of the inner conductor;

[0075] Connect point R on the right outer wall of the inner conductor to point S on the right outer wall of the inner conductor in a straight line;

[0076] Starting from point S on the outer wall of the right side of the inner conductor, with a radius of L... 16 An arc centered at point U connects to point T on the outer wall of the right side of the inner conductor.

[0077] Connect point T on the outer wall of the right side of the inner conductor to point Q on the lower wall of the inner conductor in a straight line;

[0078] Finally, after connecting all the key nodes, the flow channel profile of the left half of the fluid oscillator is formed.

[0079] Furthermore, the proportional correlation coefficient can be freely adjusted within a range of 1 ± 30% of a given empirical value.

[0080] Beneficial effects: Compared with the prior art, the significant advantage of this invention is that it establishes a full parameter correlation system based on the reference parameters. By changing the reference parameters and the proportional correlation coefficient, the parameterization design of fluid oscillators can be carried out more flexibly and quickly.

[0081] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0082] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-described method.

[0083] The present invention also provides a fluid oscillator designed using the parametric design method for the above-described aero-engine fluid oscillator. Attached Figure Description

[0084] Figure 1 This is a schematic diagram illustrating the working principle of a fluid oscillator.

[0085] Figure 2 This is a schematic diagram showing the overall key nodes and geometric parameter distribution of the fluid oscillator used in this invention.

[0086] Figure 3 This is a schematic diagram of the complete two-dimensional geometry of the fluid oscillator designed using the design method of this invention.

[0087] Figure 4 Comparison of two-dimensional geometric profiles of fluid oscillators under different proportional correlation coefficients.

[0088] Figure 5 This is a diagram showing the oscillation frequency of the fluid oscillator under different pressure ratios in this invention.

[0089] Figure 6 This is a schematic diagram of the complete three-dimensional geometry of the fluid oscillator designed using the design method of this invention. Detailed Implementation

[0090] This embodiment presents a parametric design method for a fluid oscillator in an aero-engine. The designed fluid oscillator structure is as follows: Figure 1 As shown.

[0091] Please combine Figure 2 As shown, the parameterized design method for the aero-engine fluid oscillator includes the following steps:

[0092] S1. Establish an XY coordinate system, with the center point of the fluid oscillator outlet as the origin O(0,0), the y-axis along the axis of symmetry of the fluid oscillator as the y-axis, and the horizontal direction as the x-axis. Determine the critical node O1 in the outlet throat region, and define the horizontal distance from the critical node O1 to the origin, i.e., the half-width distance L0 of the outlet throat, as the reference parameter. Specifically, in this case, L0 = 0.75 mm.

[0093] S2. Based on the reference parameter L0, determine the key geometric parameters on the flow channel profile using a proportional correlation function, which is as follows:

[0094] L x =α x ×L0

[0095] Where, α x This is the proportional correlation coefficient; the proportional correlation coefficient is determined by design experience.

[0096] In this embodiment, the specific values ​​of the proportional correlation coefficients of the key geometric parameters in each region are as follows:

[0097] (1) Parameters of the exit section: Half width of the exit L1 = α1 × L0 = 2.1 × 0.75 = 1.575 mm;

[0098] (2) Parameters of the outlet throat section: Half width of the outlet throat L0 = 0.75 mm;

[0099] (3) Parameters of the mixing cavity region: radius of the large circle on the upper wall of the mixing cavity L2=α2×L0=4.1×0.75=3.075mm; half width of the mixing cavity L3=α3×L0=3.2×0.75=2.4mm; radius of the rounding of the mixing cavity region L4=α4×L0=0.1×0.75=0.075mm;

[0100] (4) Feedback channel parameters: The radius of the upper wall arc of the feedback channel is L5 = α5 × L0 = 0.9 × 0.75 = 0.675 mm, the horizontal distance from the outer wall of the feedback channel to the y-axis is L6 = α6 × L0 = 5 × 0.75 = 3.75 mm, the height of the vertical section of the feedback channel is L7 = α7 × L0 = 6 × 0.75 = 4.5 mm, the radius of the bottom arc of the feedback channel is L8 = α8 × L0 = 2 × 0.75 = 1.5 mm, and the width of the feedback channel is L9 = α9 × L0 = 1.8 × 0.75 = 1.35 mm;

[0101] (5) Inner island segment parameters: The vertical height of the inner conductor segment is L 10 =α 10 ×L0=4.96×0.75=3.72mm, the radius of the top arc L 11 =α 11 ×L0=0.5×0.75=0.375mm, vertical height L of the left side region of the inner conductor 12 =α 12 ×L0=3.86×0.75=2.895mm, the radius L of the bottom arc on the left side of the inner conductor. 13 =α 13 ×L0=0.6×0.75=0.45mm, the horizontal distance from the bottom right point of the inner conductor to the y-axis is L. 14 =α 14 ×L0=1.2×0.75=0.9mm; The vertical height of the right side region of the inner conductor is L. 15 =α 15 ×L0=2.4×0.75=1.8mm, the radius L of the arc on the right side of the inner conductor 16 =α 16 ×L0=0.8×0.75=0.6mm.

[0102] (6) Entrance segment parameters: The minimum lateral distance of the entrance segment contraction region from the y-axis is L.17 =α 17 ×L0=0.8×0.75=0.6mm, the maximum lateral distance from the y-axis is L. 18 =α 18 ×L0=2.1×0.75=1.575mm, the vertical height of the inlet straight pipe section is L 19 =α 19 ×L0=4×0.75=3mm.

[0103] S3. Based on the key geometric parameters of each region mentioned above, and in conjunction with the geometric constraints, calculate the coordinates of each key node, as follows:

[0104] (1) Key nodes of the outer contour (left half):

[0105] The coordinates of the outlet center point O are (0,0); this point is the origin of the coordinate system and also the outlet center point of the fluid oscillator.

[0106] The coordinates of point A at the edge of the exit section are (-1.5750, 0); this point is determined by the half-width of the exit, L1 = 1.575 mm, and is located in the negative x-axis direction.

[0107] The coordinates of point O1 at the edge of the outlet throat section are (-0.75, -0.692); this point is determined by the intersection of the extension of point A along the direction of angle θ1=40° and the point where x=-L0=-0.75mm; the choice of θ1 as 40° is determined empirically.

[0108] The coordinates of point B at the edge of the hybrid cavity segment are (-2.4, -1.752). This point is obtained through the following steps: First, a circle with center O1 and radius L2 intersects the y-axis to obtain the key node O2 (0, -3.674). Then, a circle with center O2 and radius L2 intersects the x=-L3=-2.4mm point to determine the location.

[0109] The coordinates of point C on the outer wall of the feedback channel are (-3.75, -1.752). This point is determined by the intersection of a circle with radius L5 and point B on the circumference with x = -L6 = -3.75 mm. The center point D of this circle is obtained from this intersection, and its coordinates are (-2.4, -1.752).

[0110] The coordinates of point E on the outer wall of the feedback channel are (-3.75, -6.252); this point is located in the negative vertical direction of the y-axis of point C, with a vertical distance of L7;

[0111] The coordinates of point F on the lower wall of the feedback channel are (-2.25, -7.752). This point is the end point of an arc with radius L8, starting point E, and tangent direction at point E in the vertical direction. The tangent direction of the arc at point F is in the horizontal direction. From this, the center point G of the arc is obtained, with coordinates (-2.25, -6.252).

[0112] The coordinates of the vertex H in the contraction region of the entrance segment are (-0.6, -7.752); this point is located in the positive horizontal direction of the x-axis from point F, and the horizontal distance from the y-axis is L. 17 ;

[0113] The coordinates of vertex I in the contraction region of the entrance segment are (-1.575, -12.34); this point is the extension of point H along the direction of angle θ3 = 12°, intersecting x = -L. 18 The intersection point is determined at -1.575mm; θ3 is chosen as 12° based on experience.

[0114] The coordinates of the lower vertex J of the inlet straight pipe section are (-1.575, -15.34); this point is located in the negative vertical direction of the y-axis from point I, with a vertical distance of L. 19 ;

[0115] (2) Key node of inner conductor (left half)

[0116] The coordinates of point K at the top of the inner conductor are (-2.4, -2.532); this point is located at the positive horizontal x-axis and positive vertical y-axis of point E, with a horizontal distance of L9 and a vertical distance of L. 10 ;

[0117] The coordinates of the upper left wall of the inner conductor are (-2.4, -2.907); this point is located in the negative vertical direction of the y-axis from point K, with a vertical distance of L. 11 ;

[0118] The coordinates of point M on the lower left side of the inner conductor are (-2.4, -5.802); this point is located in the negative vertical direction of the y-axis of point L, with a vertical distance of L. 12 ;

[0119] The coordinates of point N on the lower wall of the inner conductor are (-1.95, -6.252); this point is a point with radius L. 13 The starting point is point M. The tangent at point M is in the vertical direction. The tangent at point N is in the horizontal direction. The center point P of the arc is obtained from this, with coordinates (-1.95, -5.802).

[0120] The coordinates of point Q on the lower wall of the inner conductor are (-0.9, -6.252); this point is located in the positive horizontal direction of the x-axis from point N, and the horizontal distance from the y-axis is L. 14 ;

[0121] The coordinates of point R on the right wall of the inner conductor are (-2.025, -2.907); this point is a circle with center L and radius L. 11 The starting point is point K, the tangent at point K is horizontal, and the terminating point of the arc is vertical.

[0122] The coordinates of point S on the right wall of the inner conductor are (-2.025, -4.707); this point is located in the negative vertical direction of the y-axis from point R, with a vertical distance of L. 15 ;

[0123] The coordinates of point T on the right wall of the inner conductor are (-1.409, -4.707); this point is located at a radius of L. 16 The starting point is point S. The circle with the tangent at point S in the vertical direction is defined by the intersection of the extension of the line from point Q along the direction of angle θ2 = 40°. The center point U of the arc is obtained from this intersection, with coordinates (-1.95, -5.802). θ2 is chosen as 40° based on experience.

[0124] S4. Connect the key nodes according to the preset connection rules to form the flow channel profile curve of the left half of the fluid oscillator, as follows:

[0125] (1) The connection sequence and method of the outer contour lines are as follows:

[0126] (a) Connect the edge point A of the exit segment from the center point O along the negative x-axis with a straight line;

[0127] (b) Connect the edge point A of the outlet section to the edge point O1 of the outlet throat section with a straight line, and round the corner at O1;

[0128] (c) Connect point O1 at the edge of the outlet throat section to point B at the edge of the mixing chamber section with an arc of radius L2 = 3.075 mm and center at point O2, and round the corner at point B;

[0129] (d) Connect point B on the edge of the mixing cavity section with an arc of radius L5 = 0.675 mm and center D to point C on the outer wall of the feedback channel;

[0130] (e) Connect point C on the outer wall of the feedback channel to point E on the outer wall of the feedback channel in a straight line;

[0131] (f) Connect point E on the outer wall of the feedback channel to point F on the lower wall of the feedback channel with an arc of radius L8 = 1.5 mm and center point G;

[0132] (g) Connect point F to point H on the lower wall of the feedback channel in a straight line;

[0133] (h) Connect point H to point I on the lower wall of the feedback channel with a straight line;

[0134] (i) Connect point I to the entry segment point J by a straight line;

[0135] (2) The connection sequence and method of the inner island outline are as follows:

[0136] (a) Connect point K at the top of the inner island to point L on the left outer wall of the inner island in a straight line;

[0137] (b) Connect the point L on the outer wall of the left side of the inner island to the point M on the lower wall of the inner island in a straight line;

[0138] (c) From point M on the lower wall of the inner island, with a radius of L 13 =0.45mm, an arc centered at point P connects to point N on the lower wall of the inner island;

[0139] (d) Connect point N on the lower wall of the inner island with a straight line to point Q on the lower wall of the inner island;

[0140] (e) From the top point K of the inner island, with a radius of L 11 =0.375mm, an arc centered at point L connects to point R on the outer wall of the right side of the inner conductor;

[0141] (f) Connect point R on the right outer wall of the inner conductor to point S on the right outer wall of the inner conductor in a straight line;

[0142] (g) From point S on the outer wall of the right side of the inner conductor, with a radius of L 16 =0.6mm, with the arc centered at U, connects to point T on the outer wall of the right side of the inner conductor;

[0143] (h) Connect point T on the outer wall of the right side of the inner conductor to point Q on the lower wall of the inner conductor in a straight line;

[0144] Finally, after connecting all the key nodes, the flow channel profile of the left half of the fluid oscillator is formed.

[0145] S5. Mirror the left half of the surface curve about the y-axis to obtain the complete two-dimensional geometry of the fluid oscillator. Then, perform spanwise stretching to obtain the three-dimensional geometry of the fluid oscillator. Figure 6 As shown.

[0146] The fluid oscillator structure obtained by the design method of the above embodiments is as follows: Figure 3 As shown.

[0147] In this example, the proportional correlation coefficient can be freely adjusted within a range of 1 ± 30% of a given empirical value, ensuring that the final flow channel profile also achieves good results. For example... Figure 4 As shown, taking the proportional correlation coefficient of the feedback channel width as an example, the proportional correlation coefficient α9 of the black solid line is 1.8, and the proportional correlation coefficient α9 of the red dashed line is 1.3. That is, when α... x With different values, the two-dimensional profile of the fluid oscillator can also change under the premise of fixed geometric constraints and geometric length.

[0148] like Figure 5As shown, the fluid oscillator designed using the above method, verified by numerical simulation, can generate a stable self-excited oscillating jet within the operating range of pressure ratio NPR = 1.5 to NPR = 3. The performance parameters, such as oscillation frequency and jet velocity, meet the engineering design requirements. This result verifies the effectiveness and practicality of the parametric design method proposed in this invention.

Claims

1. A parametric design method for aero-engine fluid oscillators, characterized in that, Includes the following steps: S1. Taking the center point of the fluid oscillator outlet as the origin O(0,0), the y-axis along the axis of symmetry of the fluid oscillator and the x-axis in the horizontal direction, determine the key node O1 in the outlet throat region, and define the horizontal distance from the key node O1 to the origin as the half-width distance L0 of the outlet throat. S2. Calculate the key geometric parameters of each region based on the half-width distance L0 of the throat in the exit section; S3. Based on the key geometric parameters of each region mentioned above, and in conjunction with the geometric constraints, calculate the coordinates of each key node. S4. Connect the key nodes according to the preset connection rules to form the flow channel profile curve of the left half of the fluid oscillator. S5. Mirror the left half of the surface curve about the y-axis to obtain the complete two-dimensional geometry of the fluid oscillator. Then, stretch the surface to obtain the complete three-dimensional geometry of the fluid oscillator.

2. The parametric design method for aero-engine fluid oscillators as described in claim 1, characterized in that, Step S2 includes the following parameters: outlet half-width L1, radius of the large arc on the upper wall of the mixing chamber L2, half-width of the mixing chamber L3, radius of the arc on the upper wall of the feedback channel L5, lateral distance from the outer wall of the feedback channel to the y-axis L6, height of the vertical section of the feedback channel L7, radius of the bottom arc of the feedback channel L8, width of the feedback channel L9, and vertical height of the inner conductor section L. 10 Top arc radius L 11 The vertical height of the left side region of the inner conductor is L. 12 The radius L of the bottom left arc of the inner conductor 13 The horizontal distance L from the bottom right point of the inner conductor to the y-axis 14 Vertical height L of the right side region of the inner conductor 15 The radius L of the right arc of the inner conductor 16 The minimum lateral distance L from the y-axis to the contraction zone of the inlet section 17 The maximum lateral distance L from the y-axis to the contraction zone of the inlet section 18 Vertical height L of the inlet straight pipe section 19 .

3. The parametric design method for aero-engine fluid oscillators as described in claim 2, characterized in that, In S2, based on the reference parameter L0, the key geometric parameters on the flow channel profile are determined through a proportional correlation function, which is as follows: L x =α x ×L0, Where, α x This is the proportional correlation coefficient.

4. The parametric design method for aero-engine fluid oscillators as described in claim 3, characterized in that, In S2, the exit half-width L1 = α1 × L0; The radius of the large circular arc on the upper wall of the mixing cavity is L2 = α2 × L0; The half-width of the mixing cavity L3 = α3 × L0; The radius of the rounding in the mixing cavity region is L4 = α4 × L0; The radius of the arc on the upper wall of the feedback channel is L5 = α5 × L0; The lateral distance from the outer wall of the feedback channel to the y-axis is L6 = α6 × L0 = 5 × 0.75; The vertical section height of the feedback channel is L7 = α7 × L0; The radius of the bottom arc of the feedback channel is L8 = α8 × L0; The feedback channel width is L9 = α9 × L0; The vertical height of the inner conductor segment is L 10 =α 10 ×L0; Top arc radius L 11 =α 11 ×L0; Vertical height L of the left side region of the inner conductor 12 =α 12 ×L0; Radius L of the bottom left arc of the inner conductor 13 =α 13 ×L0; The horizontal distance L from the bottom right point of the inner conductor to the y-axis 14 =α 14 ×L0; The vertical height of the region on the right side of the inner conductor is L. 15 =α 15 ×L0; Radius L of the right arc of the inner conductor 16 =α 16 ×L0; The minimum lateral distance of the inlet segment contraction region from the y-axis is L. 17 =α 17 ×L0; The maximum lateral distance of the inlet segment contraction region from the y-axis is L. 18 =α 18 ×L0; The vertical height of the inlet straight pipe section is L 19 =α 19 ×L0; Where α1 to α 19 This is the proportional correlation coefficient.

5. The parametric design method for an aero-engine fluid oscillator as described in claim 4, characterized in that, In step S3, the coordinates of each key node include: The coordinates of point A at the edge of the exit section are (-L1, 0). The coordinates of point O1 at the edge of the outlet throat segment are determined by the intersection of the extension of point A along the direction of angle θ1=40° and the point x=-L0. The coordinates of the edge point B of the hybrid cavity segment are determined by the intersection of a circle with center O1 and radius L2 with the y-axis to obtain the key node O2, and then the intersection of a circle with center O2 and radius L2 with x=-L3 to determine the coordinates. The coordinates of point C on the outer wall of the feedback channel are determined by the intersection of a circle with radius L5 and point B on the circumference with x=-L6, and the coordinates of the center point D of the circle are obtained from this intersection. The coordinates of point E on the outer wall of the feedback channel are determined by the vertical distance L7 from the negative y-axis at point C. The coordinates of point F on the lower wall of the feedback channel are determined by the endpoint of an arc with radius L8, starting point E, and tangent direction at point E as the vertical direction; this arc is designated as the first arc, and the tangent direction of the first arc at point F is horizontal. Coordinates of the center point G of the first arc; The coordinates of the vertex H in the contraction region of the entrance segment are: located at the positive x-axis of point F, with a horizontal distance L from the y-axis. 17 Sure; The coordinates of vertex I in the contraction region of the entrance segment: Using the extension of the line from point H along the direction of angle θ3 = 12°, intersecting x = -L... 18 The intersection point is determined; The coordinates of the lower vertex J of the inlet straight pipe section are: located vertically in the negative y-direction of the y-axis at point I, with a vertical distance of L. 19 Sure; The coordinates of the top point K of the inner conductor are: located at the positive x-axis and positive y-axis of point E, with a horizontal distance of L9 and a vertical distance of L. 10 Sure; The coordinates of the upper left wall of the inner conductor (L): The vertical distance from point K in the negative y-axis direction is L. 11 Sure; Coordinates of point M on the lower left side of the inner conductor: This point is located in the negative vertical direction of the y-axis from point L, with a vertical distance of L. 12 Sure; Coordinates of point N on the lower wall of the inner conductor: with radius L 13 The starting point is point M, and the tangent direction at point M is vertical. The ending point of the arc is determined. This arc is set as the second arc, and the tangent direction of the second arc at point N is horizontal. Coordinates of the center point P of the second arc; Coordinates of point Q on the lower wall of the inner conductor: This point is located in the positive horizontal direction of the x-axis from point N, and the horizontal distance from the y-axis is L. 14 Sure; The coordinates of point R on the right side wall of the inner conductor are: a circle with center L and radius L. 11 The starting point is point K, and the tangent direction at point K is horizontal. The ending point of the arc is determined. This arc is set as the third arc, and the tangent direction of the third arc at point R is vertical. Coordinates of point S on the right wall of the inner conductor: Located at the negative vertical direction of the y-axis at point R, with a vertical distance of L. 15 Sure; The coordinates of point T on the right wall of the inner conductor: from radius L 16 The circle with the starting point being point S and the tangent at point S being in the vertical direction is defined by the intersection of the extension of the line from point Q along the direction of angle θ2=40°. The arc between point S and point T is the fourth arc. The center point U of the fourth arc.

6. The parametric design method for an aero-engine fluid oscillator as described in claim 5, characterized in that, In S4, the connection rules include: Connect the edge point A of the exit segment from the center point O along the negative x-axis with a straight line. Connect the edge point A of the outlet section to the edge point O1 of the outlet throat section with a straight line, and perform a rounding treatment at point O1; Connect the edge point O1 of the outlet throat section to the edge point B of the mixing cavity section with an arc of radius L2 and center point O2, and perform rounding treatment at point B; Connect the edge point B of the mixing cavity section to the outer wall point C of the feedback channel with an arc of radius L5 and center point D; Connect point C on the outer wall of the feedback channel to point E on the outer wall of the feedback channel in a straight line; Connect point E on the outer wall of the feedback channel to point F on the lower wall of the feedback channel using an arc with radius L8 and center point G; Connect point F to point H on the lower wall of the feedback channel in a straight line; Connect point H to point I on the lower wall of the feedback channel with a straight line; Connect point I to the entry segment point J by a straight line; Connect point K at the top of the inner island to point L on the left outer wall of the inner island in a straight line; Connect the point L on the outer left wall of the inner island to the point M on the lower wall of the inner island in a straight line. Starting from point M on the lower wall of the inner island, with a radius of L... 13 An arc centered at point P connects to point N on the lower wall of the inner island. Connect point N on the lower wall of the inner island to point Q on the lower wall of the inner island with a straight line; Starting from the top point K of the inner island, with a radius of L 11 An arc centered at point L connects to point R on the outer wall of the right side of the inner conductor; Connect point R on the right outer wall of the inner conductor to point S on the right outer wall of the inner conductor in a straight line; Starting from point S on the outer wall of the right side of the inner conductor, with a radius of L... 16 An arc centered at point U connects to point T on the outer wall of the right side of the inner conductor. Connect point T on the outer wall of the right side of the inner conductor to point Q on the lower wall of the inner conductor in a straight line; Finally, after connecting all the key nodes, the flow channel profile of the left half of the fluid oscillator is formed.

7. The parametric design method for an aero-engine fluid oscillator as described in claim 6, characterized in that, The proportional correlation coefficient can be freely adjusted within a range of 1 ± 30% of a given empirical value.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

10. A fluid oscillator designed using the parametric design method for an aero-engine fluid oscillator according to any one of claims 1 to 7.

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