Design method, system, equipment and medium for a suction device of a static nozzle

Abstract

The present invention provides a design method, system, equipment and medium for a suction device of a static nozzle, wherein the method includes: forming a suction device including a suction slot, a suction chamber and a suction pipe by the contraction section and throat of the nozzle, including the following steps: setting a suction slot at the tail end of the contraction section of the nozzle; determining the starting position of the suction slot according to the size of the throat; determining the width of the suction slot according to the height between the starting position of the suction slot and the axis of the nozzle and the suction flow rate; determining the volume of the suction chamber and the diameter of the suction pipe according to the size of the throat and the suction flow rate, so as to solve the problem of forming a new redeveloped boundary layer flow at the suction lip, causing the suction device to introduce new disturbances.

Description

Technical Field

[0001] The present invention relates to the technical field of static wind tunnel nozzle design, and in particular to a design method, device, equipment and medium for a suction device of a static nozzle. Background Art

[0002] A static wind tunnel is a special type of ground-based simulation equipment. With the continuous development of aircraft, it is necessary to accurately predict the transition position of the aircraft boundary layer, accurately measure the aircraft's aerodynamic force and aerodynamic heat, and break away from the traditional redundant design of aerodynamic thermal protection. In wind tunnel equipment, there are many factors that affect the boundary layer transition. The test results obtained in conventional wind tunnels often differ from the actual flight results. This is because the incoming flow noise in conventional wind tunnels is an order of magnitude higher than that of the atmospheric environment. In order to simulate the low-noise flow field under actual flight conditions in ground equipment, static wind tunnels came into being. Static wind tunnels achieve low-noise flow fields in the test section through structural design, nozzle boundary layer suction, and high-precision machining of the nozzle inner surface.

[0003] In the static wind tunnel equipment, the core component that generates the static flow field is the static nozzle. The static nozzle sets a suction device at the contraction section to extract the boundary layer generated by the upstream flow of the nozzle and most of the disturbances generated by the upstream components, forming a new re-developed boundary layer flow at the suction lip, while avoiding the introduction of new disturbances by the suction device. The suction effect will directly affect the quality of the static flow field of the nozzle.

[0004] Therefore, it is urgent to propose a design method for the suction device of the static nozzle to reasonably select the suction slot position, calculate the suction slot width, realize boundary layer suction while reducing the background noise of the nozzle outlet flow field, and thus reproduce the flow field during real flight conditions. Summary of the Invention

[0005] In order to overcome the problems existing in the related art, the present disclosure provides a design method, system, equipment and medium for the suction device of a static nozzle, so as to solve the technical problem in the related art that a new redeveloped boundary layer flow is formed at the suction lip, causing the suction device to introduce new disturbances, and the suction effect directly affects the quality of the static flow field of the nozzle.

[0006] One or more embodiments of this specification provide a method for designing a suction device for a static nozzle, wherein the nozzle's contraction section and throat form a suction device comprising a suction slot, a suction cavity, and a suction pipe, comprising the following steps:

[0007] A suction slot is provided at the tail end of the contraction section of the nozzle;

[0008] Determining the starting point of the suction slit according to the throat size;

[0009] Determining the width of the suction slit according to the starting position of the suction slit, the height of the nozzle axis, and the suction flow rate;

[0010] The volume of the suction cavity and the diameter of the suction pipe are determined according to the throat size and the suction flow rate.

[0011] Preferably, the method further comprises the following steps:

[0012] The contraction section adopts a shift Witoszynski curve, and the shift Witoszynski curve of the contraction section is determined according to the tail diameter and the inlet diameter of the contraction section;

[0013] The suction lip end of the suction slit adopts a five-point interpolation curve, and the lip interpolation curve is determined according to the flow field calculation results near the suction lip;

[0014] The lower surface of the suction lip to the throat adopts an arc curve, and the radius of the arc curve of the lower surface of the lip is determined according to the radius of the throat;

[0015] The upper surface of the suction lip is tangent to the upper surface of the suction lip by a straight line with a slope.

[0016] Preferably, the method further comprises the following steps:

[0017] The static nozzle is an axisymmetric nozzle.

[0018] Preferably, the method further comprises the following steps:

[0019] The radial thickness of the suction lip end is ≤2mm, and the axial length is ≥3mm. The downstream endpoints of the lip end are respectively the left vertices of the arc curve and the straight line of the upper surface.

[0020] Preferably, the upper surface of the suction lip is tangent to the upper surface of the suction lip by a straight line with a slope, and the method further comprises the following steps:

[0021] The contraction section is followed by a vertical straight line, with a rounded transition between the two. The upper surface straight line of the lip is connected to a vertical straight line with an angle of 5 to 10 degrees with the nozzle axis to form a flow channel between the two sections.

[0022] Preferably, the method further comprises the following steps:

[0023] The distance between the contraction section and the throat section is expressed as:

[0024] d = (4-5) b;

[0025] Wherein, b represents the width of the suction slit.

[0026] Preferably, the method further comprises the following steps:

[0027] The width of the suction slit should meet Among them, hc It is the height from the suction lip to the nozzle axis.

[0028] One or more embodiments of the present specification provide a system for designing a suction device for a static nozzle, wherein the nozzle's contraction section and throat form a suction device comprising a suction slot, a suction cavity, and a suction pipe, and includes a suction slot setting module, a starting position determination module, a width determination module, and a volume and diameter determination module;

[0029] The suction slot setting module is used to set a suction slot at the tail end of the contraction section of the nozzle;

[0030] The starting point position determination module is used to determine the starting point position of the suction slit according to the throat size;

[0031] The width determination module is used to determine the width of the suction slot according to the starting position of the suction slot, the height of the nozzle axis, and the suction flow rate;

[0032] The volume and diameter determination module is used to determine the volume of the suction cavity and the diameter of the suction pipe according to the throat size and the suction flow rate.

[0033] One or more embodiments of the present specification provide a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for designing a suction device for the static nozzle as described above when executing the computer program.

[0034] One or more embodiments of the present specification provide a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the steps of the method for designing a suction device of a static nozzle are implemented.

[0035] The present invention discloses a design method, system, equipment and medium for a suction device of a static nozzle, which has the advantages of providing a suction slot at the tail end of the contraction section of the nozzle and reasonably selecting the position of the suction slot to achieve suction of the boundary layer; determining the starting position of the suction slot according to the throat size, the position of the suction slot can be precisely designed to improve the suction effect; determining the width of the suction slot according to the starting position of the suction slot and the height of the axis of the nozzle and the suction flow rate, and accurately designing the starting position of the suction slot, the width of the suction slot, etc., so that the Mach number of the flow field at the lip is between 0.5 and 0.6, and the suction flow rate is 30% to 40% of the mainstream, thereby avoiding suction disturbance to the mainstream flow field; determining the volume of the suction chamber and the diameter of the suction pipe according to the throat size and the suction flow rate, and reasonably designing the volume of the suction chamber and the number and diameter of the suction pipes to ensure suction efficiency and prevent flow congestion in the suction pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 A schematic flow chart of a design method for a suction device of a static nozzle provided in one or more embodiments of this specification;

[0038] Figure 2 A schematic diagram of a static nozzle boundary layer suction design provided for one or more embodiments of this specification;

[0039] Figure 3 A schematic diagram of the suction curve size design provided for one or more embodiments of this specification;

[0040] Figure 4 A schematic structural diagram of a design system for a suction device of a static nozzle provided in one or more embodiments of this specification;

[0041] Figure 5 A schematic diagram of the structure of a computer device provided in one or more embodiments of this specification.

[0042] Reference numerals:

[0043] 1-contraction segment, 2-suction cavity, 3-expansion segment, 4-throat, 5-suction lip, 6-suction tube, I-shift Witoszynski curve, me segment-lip lower surface curve (arc), mn segment-lip end curve (five-point interpolation), nk segment-lip upper surface curve (straight line with tilt angle), (x s ,y s )-Coordinates of the end point of the contraction segment. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below in conjunction with the drawings in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this invention.

[0045] The present invention will be described in detail below with reference to specific implementation methods and the accompanying drawings.

[0046] Method Example

[0047] According to an embodiment of the present invention, a method for designing a suction device of a static nozzle is provided, such as Figure 1 FIG. 1 is a flow chart of a method for designing a suction device for a static nozzle according to an embodiment of the present invention. The method for designing a suction device for a static nozzle according to an embodiment of the present invention forms a suction device including a suction slit, a suction cavity, and a suction pipe by forming a nozzle's contraction section and a throat, and includes the following steps:

[0048] S110, setting a suction slot at the tail end of the contraction section of the nozzle, the static nozzle is an axisymmetric nozzle, the starting point of the suction slot is located upstream of the throat, and the axial distance from the throat origin is L1 = (2-3)R h , where R h represents the nozzle throat radius.

[0049] S120: Determine the starting point of the suction slit according to the throat size.

[0050] S130, determine the width of the suction slit according to the starting position of the suction slit, the height of the axis of the nozzle and the suction flow rate, which should meet Among them, h c Represents the height from the suction lip to the nozzle axis,

[0051] S140: Determine the volume of the suction cavity and the diameter of the suction pipe according to the throat size and the suction flow rate.

[0052] In one possible implementation, the suction chamber volume Where M represents the nozzle exit Mach number and π represents pi.

[0053] The suction tubes are evenly distributed along the outer circumference of the suction cavity, and each diameter Where n represents the number of suction pipes, n≥8, and s represents the area of ​​the suction slit.

[0054] Figure 2 Schematic diagram of the static nozzle boundary layer suction design provided in this embodiment.

[0055] The method provided in this embodiment achieves suction of the boundary layer by providing a suction slot at the tail end of the contraction section of the nozzle and rationally selecting the position of the suction slot; the starting position of the suction slot is determined according to the throat size, so that the position of the suction slot can be precisely designed to improve the suction effect; the width of the suction slot is determined according to the starting position of the suction slot and the height of the nozzle axis and the suction flow rate, and by precisely designing the starting position of the suction slot, the width of the suction slot, etc., the Mach number of the flow field at the lip is between 0.5 and 0.6, and the suction flow rate is 30% to 40% of the mainstream, thereby avoiding suction disturbance of the mainstream flow field; the volume of the suction chamber and the diameter of the suction pipe are determined according to the throat size and the suction flow rate, and the volume of the suction chamber and the number and diameter of the suction pipes are rationally designed to ensure suction efficiency and prevent flow congestion in the suction pipe.

[0056] In one embodiment, the following steps are further included:

[0057] The contraction section adopts a shift-axis Witoszynski curve, and the shift-axis Witoszynski curve of the contraction section is determined according to the tail diameter and the inlet diameter of the contraction section.

[0058] A five-point interpolation curve is used at the end of the suction lip of the suction slot, and the lip interpolation curve is determined according to the calculation results of the flow field near the suction lip.

[0059] The lower surface of the suction lip is connected to the throat by an arc curve. The radius of the arc curve of the lower surface of the lip is determined according to the throat radius, which can be expressed as R = (25-30)R h , the slope of the arc is zero at the throat.

[0060] The upper surface of the suction lip is tangent to the upper surface of the suction lip by a straight line with a slope.

[0061] The method provided in this embodiment designs the curve of the upper surface of the lip by making a straight line with a slope tangent to the suction lip, thereby reducing the flow disturbance caused by the curve and adjusting the suction flow rate by adjusting the installation distance between the two sections.

[0062] In one embodiment, the radial thickness of the suction lip end is ≤2mm, and the axial length is ≥3mm. The downstream endpoints of the lip end are the left vertices of the arc curve and the straight line of the upper surface, respectively, and the positions of the other three points are adjustable.

[0063] The method provided in this embodiment designs the position of the lip end curve by setting the radial thickness and axial length of the suction lip.

[0064] In one embodiment, the following steps are further included:

[0065] The downstream end point position x of the contraction section s =-L1+0.5R h ,ys =h c +b, the contraction section curve is followed by a vertical straight line, and a rounded transition is adopted between the contraction section curve and the vertical straight line segment. The upper surface straight line of the lip is connected to the nozzle axis at an angle of 5 to 10° and then connected to a vertical straight line to form a flow channel between the two sections. The distance between the contraction section and the throat section is d = (4 to 5)b, where b represents the width of the suction gap.

[0066] The method provided in this embodiment ensures that the lip curve is tangent to the arc curve upstream of the throat by designing the lip curve. The curvature of the entire suction curve is continuous and no new disturbance is caused after suction.

[0067] The following is further explained through specific implementation cases:

[0068] like Figure 3 As shown in FIG. , it is a schematic diagram of the suction curve size design provided in this embodiment.

[0069] A static nozzle boundary layer suction design method includes the following steps:

[0070] (1) The curve design takes the nozzle throat origin as the starting point, and the arc radius is calculated according to the nozzle throat size;

[0071] (2) Determine the axial length of the arc according to the throat radius and obtain the curve me;

[0072] (3) Select the length and thickness of the lip end, obtain the coordinates of point n, set the coordinates of the other three points, perform five-point interpolation, and the curve and segment me are tangent at point m;

[0073] (4) Calculate the slope of the nk curve so that it is tangent to the mn curve at point n;

[0074] (5) Calculate the suction seam width b based on the relationship between the suction seam and the lip height;

[0075] (6) Calculate the distance d between the contraction section and the throat section based on the suction gap width;

[0076] (7) Calculate the coordinates of the end point of the contraction section and design the contraction section curve based on the nozzle inlet diameter;

[0077] (8) Calculate the volume of the suction chamber, design the number of suction tubes in the circumferential direction, and calculate the diameter of the suction tubes.

[0078] When designing the curve, first determine the radius of the arc curve based on the radius of the nozzle throat. Then, select the relevant parameters based on the design method defined for each curve segment. After the design is completed, calculate the nozzle flow field. When there is no separation near the lip and no vortex structure in the boundary layer, the design is complete.

[0079] System Example

[0080] According to an embodiment of the present invention, a system for designing a suction device for a static nozzle is provided. Figure 4 As shown, it is a structural schematic diagram of the suction device design system of the static nozzle provided in this embodiment. According to the suction device design system of the static nozzle according to the embodiment of the present invention, the suction device including a suction slot, a suction cavity and a suction pipe is formed by the contraction section and the throat of the nozzle, including a suction slot setting module 41, a starting position determination module 42, a width determination module 43 and a volume and diameter determination module 44.

[0081] The suction slot setting module 41 is used to set a suction slot at the tail end of the contraction section of the nozzle.

[0082] The starting point position determining module 42 is configured to determine the starting point position of the suction slit according to the throat size.

[0083] The width determination module 43 is used to determine the width of the suction slot according to the starting position of the suction slot, the height of the nozzle axis, and the suction flow rate.

[0084] The volume and diameter determination module 44 is configured to determine the volume of the suction cavity and the diameter of the suction pipe according to the throat size and the suction flow rate.

[0085] In the device provided in this embodiment, the suction slot setting module 41 sets a suction slot at the tail end of the contraction section of the nozzle and reasonably selects the position of the suction slot to achieve suction of the boundary layer; the starting position determination module 42 determines the starting position of the suction slot according to the throat size, which can finely design the position of the suction slot and improve the suction effect; the width determination module 43 determines the width of the suction slot according to the starting position of the suction slot and the height of the nozzle axis and the suction flow rate. By accurately designing the starting position of the suction slot, the width of the suction slot, etc., the Mach number of the flow field at the lip is between 0.5 and 0.6, and the suction flow rate is 30% to 40% of the mainstream, thereby avoiding suction disturbance of the mainstream flow field; the volume and diameter determination module 44 determines the volume of the suction chamber and the diameter of the suction pipe according to the throat size and the suction flow rate, and reasonably designs the volume of the suction chamber and the number and diameter of the suction pipes to ensure suction efficiency and prevent flow congestion in the suction pipe.

[0086] The embodiment of the present invention is an apparatus embodiment corresponding to the above-mentioned method embodiment. The specific operations of the processing steps of each module can be understood by referring to the description of the method embodiment, and will not be repeated here.

[0087] like Figure 5 As shown, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which implements the design method of the suction device in the above-mentioned embodiment when the computer program is executed by a processor, or implements the design method of the suction device of the static nozzle in the above-mentioned embodiment when the computer program is executed by a processor.

[0088] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0089] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the device or system embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For the relevant parts, refer to the partial description of the method embodiments. The device and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. A person of ordinary skill in the art can understand and implement it without making any creative efforts.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and the contents not described in detail in the specification of the present invention are common knowledge to those skilled in the art.

Claims

1. A method for designing a suction device for a static nozzle, characterized in that: The suction device including a suction slot, a suction cavity and a suction pipe is formed by the contraction section and the throat of the nozzle, comprising the following steps: A suction slot is provided at the tail end of the contraction section of the nozzle; Determining the starting point of the suction slit according to the size of the throat; Determining the width of the suction slit according to the starting position of the suction slit, the height of the nozzle axis, and the suction flow rate; The volume of the suction cavity and the diameter of the suction pipe are determined according to the size of the throat and the suction flow rate.

2. The method for designing a suction device according to claim 1, wherein: The following steps are also included: The contraction section adopts a shift Witoszynski curve, and the shift Witoszynski curve of the contraction section is determined according to the tail diameter and the inlet diameter of the contraction section; The suction lip end of the suction slit adopts a five-point interpolation curve, and the lip interpolation curve is determined according to the flow field calculation results near the suction lip; The lower surface of the suction lip to the throat adopts an arc curve, and the radius of the arc curve of the lower surface of the lip is determined according to the radius of the throat; The upper surface of the suction lip is tangent to the upper surface of the suction lip by a straight line with a slope.

3. The method for designing a suction device according to claim 1, wherein: The following steps are also included: The static nozzle is an axisymmetric nozzle.

4. The method for designing a suction device according to claim 2, wherein: The following steps are also included: The radial thickness of the suction lip end is ≤2mm, and the axial length is ≥3mm. The downstream endpoints of the lip end are respectively the left vertices of the arc curve and the straight line of the upper surface.

5. The method for designing a suction device according to claim 2, wherein: The upper surface of the suction lip is tangent to the upper surface of the suction lip by a straight line with a slope, and the method further comprises the following steps: The contraction section is followed by a vertical straight line, with a rounded transition between the two. The upper surface straight line of the lip is connected to a vertical straight line with an angle of 5 to 10 degrees with the nozzle axis, forming a flow channel between the two sections.

6. The method for designing a suction device according to claim 1, wherein: The following steps are also included: The distance between the contraction section and the throat is expressed as: d=(4~5)b; Wherein, b represents the width of the suction slit.

7. The method for designing a suction device according to claim 2, wherein: The following steps are also included: The width of the suction slit should meet , where h c is the height from the suction lip to the nozzle axis, where b represents the width of the suction gap.

8. A suction device design system for a static nozzle, characterized in that: The suction device including a suction slot, a suction cavity and a suction pipe is formed by the contraction section and the throat of the nozzle, and includes a suction slot setting module, a starting position determination module, a width determination module and a volume and diameter determination module; The suction slot setting module is used to set a suction slot at the tail end of the contraction section of the nozzle; The starting point position determining module is used to determine the starting point position of the suction slit according to the size of the throat; The width determination module is used to determine the width of the suction slot according to the starting position of the suction slot, the height of the nozzle axis, and the suction flow rate; The volume and diameter determination module is used to determine the volume of the suction cavity and the diameter of the suction pipe according to the size of the throat and the suction flow rate.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for designing the suction device of the static nozzle according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for designing a suction device of a static nozzle according to any one of claims 1 to 7 are implemented.

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