A rod-type nozzle structure with adjustable throat area

Abstract

This invention discloses a tie-rod type nozzle structure with adjustable throat area, relating to the field of fluid machinery, aiming to solve the technical problem that existing fixed nozzles cannot achieve stepless adjustment of the throat area. It includes a fixed nozzle, a movable nozzle sleeved on the rear section of the fixed nozzle, an inner cone forming an exhaust channel, and multiple tie-rod assemblies distributed circumferentially. The two ends of each tie-rod assembly are connected to the fixed nozzle and the movable nozzle respectively, and their lengths are adjustable. By synchronously rotating the double-ended studs of each tie-rod assembly, the movable nozzle can be driven to slide axially relative to the fixed nozzle, changing the axial relative position of the movable nozzle outlet and the inner cone, thereby achieving stepless and continuous adjustment of the nozzle throat area. This invention has a simple and reliable structure, is convenient and flexible to operate, and only requires one device to meet a wide range of flow rate adjustment needs, significantly reducing the cost and cycle of multi-scheme matching tests, making it particularly suitable for application scenarios such as matching tests of aero-engine exhaust systems.

Description

Technical Field

[0001] This invention relates to flow channel regulation technology in the field of fluid machinery, and more particularly to a rod-type nozzle structure with adjustable throat area, which is especially suitable for adjusting the cross-sectional area of ​​the exhaust system nozzle throat during the whole-machine matching test of the exhaust system and the main engine of an aero-turbine engine. Background Technology

[0002] In fluid machinery and pipeline systems, precise flow regulation and control are crucial for ensuring system performance matching and stable operation. For general industrial pipelines, flow regulation is often achieved using various types of valves. However, under high flow conditions, conventional valves are insufficient for direct and precise flow regulation and control.

[0003] This technical challenge is particularly prominent in the research and development testing of aero-turbine engines. Aero-turbine engines are high-flow-rate fluid machines. During the overall matching test of the main engine and the exhaust system, it is necessary to adjust the operating state and flow characteristics of the main engine by changing the throat area of ​​the exhaust nozzle in order to study the matching performance of the two and select the optimal aerodynamic parameters.

[0004] Currently, there are two main methods to achieve this goal. One is to use adjustable nozzles, which have complex internal actuation mechanisms that can adjust the nozzle area in real time according to the host parameters. However, this type of nozzle is complex in structure, heavy, and expensive, making it unsuitable for use in experimental research phases that require frequent adjustments and disassemblies. The other method is to use fixed nozzles for multi-scheme comparative experiments. During the experiment, multiple sets of nozzles with different fixed throat areas need to be designed and manufactured in advance, and each set is replaced one by one for performance testing. This method has obvious technical drawbacks: high design and manufacturing costs and long cycle time; repeated disassembly and assembly of different sets of nozzles during the experiment is extremely inconvenient, time-consuming, and labor-intensive; most importantly, its adjustment range is limited to a few pre-designed discrete dimensions, and it cannot achieve stepless adjustment within a certain range. If the optimal matching point happens to fall between two preset areas, it cannot be accurately captured, seriously affecting the integrity and accuracy of the experimental data.

[0005] Therefore, how to provide a fixed nozzle device that is simple in structure, easy to operate, low in cost, and capable of stepless adjustment of the throat area has become an urgent technical problem to be solved in fields such as aero-engine matching tests. Summary of the Invention

[0006] The present invention aims to solve the above-mentioned technical problems existing in the flow matching test of existing fixed nozzles, and provides a rod-type nozzle structure with adjustable throat area that is simple and reliable in structure, convenient and flexible in operation, and can realize stepless adjustment of throat area.

[0007] To achieve the above objectives, the present invention provides a tie-rod type nozzle structure with adjustable throat area, comprising: a fixed nozzle, the front end of which is fixedly connected to an upstream main unit; a movable nozzle, the front section of which is axially slidably sleeved on the outside of the rear section of the fixed nozzle; an inner cone disposed inside the fixed nozzle and the movable nozzle, the front end of which is fixedly connected to the upstream main unit, the inner cone together with the fixed nozzle and the movable nozzle forming an exhaust channel; and a plurality of tie rod assemblies distributed circumferentially, the two ends of each tie rod assembly being connected to the fixed nozzle and the movable nozzle respectively, the length of the tie rod assembly being adjustable; by adjusting the length of the tie rod assembly, the movable nozzle is driven to slide axially relative to the fixed nozzle, thereby changing the axial relative position between the outlet of the movable nozzle and the inner cone, so as to achieve stepless adjustment of the nozzle throat area.

[0008] Furthermore, the fixed nozzle includes a converging section and a straight section connected sequentially along the fluid direction, and the movable nozzle includes a straight section and a converging section connected sequentially along the fluid direction. The straight section of the movable nozzle is axially slidably sleeved on the outside of the straight section of the fixed nozzle.

[0009] Furthermore, a limiting ring is provided on the outer surface of the straight section of the fixed nozzle, the limiting ring being used to block and limit the front end face of the moving nozzle.

[0010] Furthermore, the outer surfaces of the fixed nozzle and the movable nozzle are respectively provided with an equal number of front mounting seats and rear mounting seats with the same circumferential distribution angle, and the two ends of each tie rod assembly are respectively connected to the corresponding front mounting seat and the rear mounting seat.

[0011] Furthermore, the number of the front mounting base and the rear mounting base are 3 to 6 respectively.

[0012] Furthermore, the pull rod assembly includes a front lug, a rear lug, and a double-ended stud; the front lug is hinged to the front mounting base via a front pin, and the rear end of the front lug has an internal threaded hole; the rear lug is hinged to the rear mounting base via a rear pin, and the front end of the rear lug has an internal threaded hole, and the internal thread of the rear lug has the opposite direction of rotation to that of the front lug; the threads at both ends of the double-ended stud have opposite directions of rotation and engage with the internal threaded holes of the front lug and the rear lug, respectively, and the overall length of the pull rod assembly is adjusted by rotating the double-ended stud.

[0013] Furthermore, the tie rod assembly also includes a front nut and a rear nut. The front nut is screwed onto the double-ended stud and is tightly against the front lug to lock and prevent loosening. The rear nut is screwed onto the double-ended stud and is tightly against the rear lug to lock and prevent loosening.

[0014] Furthermore, a reinforcing ring is provided at the outlet of the movable nozzle.

[0015] Furthermore, a retaining ring is provided at the front end of the straight section of the moving nozzle.

[0016] Furthermore, a fixed nozzle mounting edge is provided at the front end of the fixed nozzle; the inner cone includes, from front to back, an inner cone mounting edge, a front section of the inner cone, and a rear section of the inner cone; the front section of the inner cone is cylindrical, and the rear section of the inner cone is conical.

[0017] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: (1) The present invention provides a tie-rod type nozzle structure with adjustable throat area. By setting a fixed nozzle, a movable nozzle, and multiple tie-rod assemblies of adjustable length connecting the two, a structural system with good overall rigidity and axial adjustment is formed. When it is necessary to adjust the throat area, it is only necessary to rotate the circumferentially distributed tie-rod assemblies, which can precisely and smoothly drive the movable nozzle to slide axially along the outer wall of the fixed nozzle through threaded transmission, thereby changing the axial relative position between the outlet of the movable nozzle and the fixed inner cone, realizing continuous and stepless adjustment of the nozzle throat area over a wide range. This adjustment process does not require the replacement of any parts, and the operation is extremely convenient and flexible.

[0018] (2) This invention completely abandons the traditional approach of manufacturing multiple sets of fixed nozzles to match different throat areas. A single device can cover a continuous adjustment range, greatly reducing testing costs and development cycle. At the same time, the device has a simple overall structure, with the main components being rotating bodies or simple structural parts. It has good manufacturability, is easy to assemble, has high structural reliability, and is very convenient to operate and maintain on test benches with limited space. It perfectly solves the technical problems raised in the background art and has broad application prospects. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 This is an isometric schematic diagram of the adjustable throat area nozzle structure provided by the present invention.

[0021] Figure 2 This is a front view of the adjustable throat area nozzle structure provided by the present invention.

[0022] Figure 3 for Figure 2 View from direction A.

[0023] Figure 4 for Figure 3 BB section view.

[0024] Figure 5 for Figure 4 Enlarged view of point C in the middle.

[0025] Reference numerals: 1-First connector; 2-Fixed nozzle; 3-Tie rod assembly; 4-Moving nozzle; 5-Inner cone; 21-Fixed nozzle mounting edge; 22-Fixed nozzle converging section; 23-Front mounting seat; 24-Fixed nozzle straight section; 25-Restricting ring; 31-Front pin; 32-Front lifting lug; 33-Front stud head; 34-Front nut; 35-Rear stud head; 36-Rear nut; 37-Rear lifting lug; 38-Rear pin; 41-Sticking ring; 42-Moving nozzle straight section; 43-Rear mounting seat; 44-Moving nozzle converging section; 45-Reinforcing ring; 51-Second connector; 52-Inner cone mounting edge; 53-Front section of inner cone; 54-Rear section of inner cone. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be noted that in the description of this invention, the terms "front," "rear," "upstream," "downstream," "axial," and "circumferential," etc., indicate the orientation or positional relationship based on the fluid flow direction and the installation state of the nozzle during operation, with the fluid flow direction being from front to back. These terms are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0028] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0029] See Figures 1 to 5 This invention provides a tie-rod type nozzle structure with adjustable throat area. The device mainly consists of a fixed nozzle 2, a movable nozzle 4, an inner cone 5, and multiple tie-rod assemblies 3.

[0030] The fixed nozzle 2 constitutes the front main body of the device. Its frontmost end is designed with a fixed nozzle mounting edge 21, on which multiple bolt holes are formed circumferentially. Through a first connecting component 1 (such as bolts or rivets), the fixed nozzle mounting edge 21 can achieve a robust and reliable flange connection with the upstream main unit (e.g., the turbine support structure of an aero-turbine engine). The internal flow channel of the fixed nozzle 2 is defined by its converging section 22 and straight section 24, which are part of its shell shape. The converging section 22 is used to rectify and accelerate the incoming flow, and its internal cross-sectional area gradually decreases along the flow direction. To ensure structural integrity and strength, the fixed nozzle mounting edge 21, the converging section 22, and the straight section 24 can be connected by welding, riveting, or integral forming. Multiple front mounting seats 23 are welded evenly circumferentially onto the outer surface of the converging section 22 for connecting the front end of the tie rod assembly 3. Preferably, all front mounting seats 23 should be located in the same axial position to ensure the synchronization and consistency of adjustment. Their number should be reasonably set according to the nozzle diameter, preferably 3 to 6; in this embodiment, 6 are used. Furthermore, a limiting ring 25 is fixedly installed on the outer surface of the straight section 24 of the fixed nozzle, at a certain axial position from its outlet end face. This limiting ring 25 can be a continuous annular structure or protrusions discontinuously distributed circumferentially, and its outer diameter is larger than the diameter of the inner wall or end face of the front end of the straight section 42 of the moving nozzle. The core function of the limiting ring 25 is to mechanically block the front end face of the moving nozzle 4 when it slides forward to its limit position, preventing excessive forward movement and providing a reliable limiting function.

[0031] The inner cone 5 is located at the center of the fixed nozzle 2 and the moving nozzle 4, and is the core component constituting the inner wall of the flow channel. Its front end is fixedly connected to the upstream main unit through the inner cone mounting edge 52 and the second connector 51. The inner cone 5 consists of the inner cone mounting edge 52, the inner cone front section 53, and the inner cone rear section 54 from front to back. The inner cone front section 53 is cylindrical and is used to provide an initial uniform cross-section flow channel; the inner cone rear section 54 is conical, and its outer diameter gradually decreases from front to back, forming a variable throat area in conjunction with the moving nozzle convergent section 44. The tail of the inner cone rear section 54 is designed to be long enough in the axial position to extend beyond the axial position of the throat of the moving nozzle 4, so as to ensure that the throat cross-section of the flow channel is always formed by the inner edge of the outlet of the moving nozzle 4 and the outer wall of the inner cone rear section 54 throughout the entire stroke of the moving nozzle 4, thus ensuring the accuracy and consistency of throat area adjustment. The inner cone mounting edge 52, the front section 53 and the rear section 54 of the inner cone should preferably be integrally formed, or they can be connected by welding or riveting.

[0032] The movable nozzle 4 constitutes the rear movable main body of the device. It mainly consists of a front movable nozzle straight section 42 and a rear movable nozzle converging section 44. The inner diameter of the movable nozzle straight section 42 is slightly larger than the outer diameter of the fixed nozzle straight section 24, forming a precise clearance fit. The design requirements of this clearance fit are: to ensure that the movable nozzle 4 can slide smoothly along the axial direction relative to the fixed nozzle 2 without jamming, and to effectively prevent significant leakage of high-pressure gas in the internal flow channel from this gap, so as to ensure the accuracy of aerodynamic performance. A retaining ring 41 is provided at the front end of the movable nozzle straight section 42. The inner diameter of the retaining ring 41 contacts the outer surface of the fixed nozzle straight section 24. The retaining ring 41 serves two purposes: firstly, to provide reinforcement, and secondly, to contact the limiting ring 25, increasing the contact area. At the exit of the converging section 44 of the moving nozzle, a reinforcing ring 45 is designed to enhance the structural rigidity and roundness of the exit end face, preventing changes in the exit shape due to airflow pressure or thermal deformation, thereby ensuring the accuracy and stability of the throat area. On the outer surface of the straight section 42 of the moving nozzle, multiple rear mounting seats 43 are also uniformly distributed circumferentially and fixed. The number and installation angle of the rear mounting seats 43 must correspond one-to-one with and be consistent with the front mounting seats 23, and all rear mounting seats 43 are located in the same axial position. The straight section 42, converging section 44, retaining ring 41, reinforcing ring 45, and other components of the moving nozzle 4 can be manufactured by welding, riveting, or integral forming.

[0033] The tie rod assembly 3 is the core transmission component that connects the fixed nozzle 2 and the moving nozzle 4 and enables length adjustment. Each tie rod assembly 3 consists of a front connecting assembly, a rear connecting assembly, and a double-ended stud.

[0034] Specifically, the front connecting assembly includes a front lug 32 and a front pin 31. The front lug 32 is hinged to the front mounting base 23 on the fixed nozzle 2 via the front pin 31, allowing the front lug 32 to swing freely within a certain angle around the front pin 31 to compensate for minor coaxiality deviations that may occur during installation and movement. The rear end of the front lug 32 has an internally threaded hole of a certain depth along the axial direction.

[0035] symmetrically, the rear connecting assembly includes a rear lug 37 and a rear pin 38. The rear end of the rear lug 37 is hinged to a rear mounting seat 43 on the movable nozzle 4 via the rear pin 38, allowing it to swing freely. The front end of the rear lug 37 also has an internally threaded hole along the axial direction. A key technical feature is that the internal thread direction at the rear end of the front lug 32 is designed to be opposite to that at the front end of the rear lug 37. For example, one is a right-hand thread, and the other is a left-hand thread.

[0036] The double-ended stud is the core screw connecting the two parts. It is a single, integrally formed part with two threaded sections: a front stud head 33 and a rear stud head 35. The threads of these two heads must be in completely opposite directions to correspond to and screw into the threaded holes of the front lug 32 and the rear lug 37, respectively. To ensure that it will not loosen under vibration, a front nut 34 and a rear nut 36 are respectively provided on the front stud head 33 and the rear stud head 35. After the engagement length of the double-ended stud is adjusted, tighten the front nut 34 so that its end face is tightly against the end face of the front lug 32, and tighten the rear nut 36 so that its end face is tightly against the end face of the rear lug 37, thereby achieving reliable mechanical locking. The nuts can be self-locking nuts, or ordinary nuts can be used with locking screws for anti-loosening treatment.

[0037] The working principle and assembly / use process of this device are as follows: First, the fixed nozzle 2, tie rod assembly 3, movable nozzle 4, and inner cone 5 are pre-assembled into a single unit. Specifically, the straight section 42 of the movable nozzle 4 is fitted onto the outside of the straight section 24 of the fixed nozzle 2, forming a sliding fit. Then, the front lug 32 and rear lug 37 of each tie rod assembly 3 are mounted on the corresponding front mounting base 23 and rear mounting base 43 via the front pin 31 and rear pin 38, respectively.

[0038] Next, this entire assembly is installed onto the upstream main unit. First, the inner cone 5 is fixedly connected to the main unit via its inner cone mounting edge 52 and the second connector 51. Then, the fixed nozzle 2 is fixedly connected to the main unit via its fixed nozzle mounting edge 21 and the first connector 1. At this point, the fixed part of the nozzle and the internal flow channel profile are determined.

[0039] When throat area adjustment is required, the operator only needs to use a wrench or other tools to rotate the double-ended studs in the middle of all the tie rod assemblies 3. Since the threads at both ends of the double-ended studs rotate in opposite directions and engage with the front and rear lugs rotating in opposite directions respectively, rotating the double-ended studs causes the front lug 32 and the rear lug 37 to simultaneously and symmetrically move closer or further away along the axial direction. Specifically, when rotating in one direction, the distance L between the front and rear lugs increases, thereby pushing the moving nozzle 4 to slide backward (downstream) along the outer wall of the fixed nozzle 2. As the moving nozzle 4 moves backward, the cross-sectional area of ​​the annular channel between the inner edge of the converging section 44 of the moving nozzle at its outlet and the outer wall of the rear section 54 of the inner cone increases, i.e., the throat area S increases. Conversely, when rotating the double-ended studs in the opposite direction, the distance L decreases, and the tie rod assembly 3 pulls the moving nozzle 4 forward (upstream), thus reducing the annular throat area between the outlet of the moving nozzle 4 and the rear section 54 of the inner cone. When the movable nozzle 4 slides forward to its limit position, its leading edge will contact the limiting ring 25 on the straight section 24 of the fixed nozzle, achieving reliable mechanical limiting and effectively preventing excessive forward movement. (Refer to...) Figure 4 and Figure 5 By changing the distance L, the difference between the exit radius R2 of the moving nozzle 4 and the radius R1 of the rear section 54 of the inner cone at the corresponding axial position can be controlled, thereby achieving stepless and continuous adjustment of the throat cross-sectional area S. After adjustment, tightening all the locking nuts 34 and 36 will lock the throat area state.

[0040] During the adjustment process, it is crucial to ensure that the adjustment amounts of all tie rod assemblies 3 are strictly consistent, meaning that the distance L between the front and rear lifting lugs in each tie rod assembly 3 must be exactly equal. This is essential for ensuring that the exit section of the moving nozzle 4 remains perpendicular to the axis of the entire device, thereby obtaining a uniform and symmetrical exhaust flow field, and is also key to ensuring the accuracy of the test data.

[0041] In summary, the present invention provides a tie-rod type nozzle structure with adjustable throat area. Through the innovative spiral adjustment mechanism of the "tie-rod assembly", the moving nozzle is driven to slide axially, which ingeniously transforms the rotational operation into linear adjustment motion, realizing a large-range stepless adjustment of the nozzle throat area. It perfectly overcomes the defects of discrete adjustment, high cost and inconvenient operation in the traditional fixed nozzle test scheme, and has high practical value and broad application prospects.

[0042] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A rod-type nozzle structure with adjustable throat area, characterized in that, include: Fixed nozzle (2), the front end of which is used for fixed connection with the upstream host; The movable nozzle (4) has its front section axially slidably fitted onto the outside of the rear section of the fixed nozzle (2); An inner cone (5) is disposed inside the fixed nozzle (2) and the movable nozzle (4), and its front end is used to be fixedly connected to the upstream host. The inner cone (5), the fixed nozzle (2) and the movable nozzle (4) together form an exhaust channel. Multiple tie rod assemblies (3) are distributed circumferentially, and the two ends of each tie rod assembly (3) are respectively connected to the fixed nozzle (2) and the movable nozzle (4), and the length of the tie rod assembly (3) is adjustable; By adjusting the length of the tie rod assembly (3), the movable nozzle (4) is driven to slide axially relative to the fixed nozzle (2), thereby changing the axial relative position between the outlet of the movable nozzle (4) and the inner cone (5) to achieve stepless adjustment of the nozzle throat area.

2. The adjustable throat area nozzle structure according to claim 1, characterized in that, The fixed nozzle (2) includes a fixed nozzle converging section (22) and a fixed nozzle straight section (24) connected in sequence along the fluid direction. The movable nozzle (4) includes a movable nozzle straight section (42) and a movable nozzle converging section (44) connected in sequence along the fluid direction. The movable nozzle straight section (42) is axially slidably sleeved on the outside of the fixed nozzle straight section (24).

3. The adjustable throat area nozzle structure according to claim 2, characterized in that, A limiting ring (25) is provided on the outer surface of the straight section (24) of the fixed nozzle. The limiting ring (25) is used to block and limit the front end face of the moving nozzle (4).

4. The adjustable throat area nozzle structure according to claim 1, characterized in that, The outer surfaces of the fixed nozzle (2) and the outer surfaces of the movable nozzle (4) are respectively provided with an equal number of front mounting seats (23) and rear mounting seats (43) with the same circumferential distribution angle. The two ends of each tie rod assembly (3) are respectively connected to the corresponding front mounting seat (23) and rear mounting seat (43).

5. The adjustable throat area nozzle structure according to claim 4, characterized in that, The number of the front mounting bracket (23) and the rear mounting bracket (43) are 3 to 6 respectively.

6. The adjustable throat area nozzle structure according to claim 4, characterized in that, The tie rod assembly (3) includes a front lug (32), a rear lug (37), and a double-ended stud; The front lug (32) is hinged to the front mounting base (23) via a front pin (31), and the rear end of the front lug (32) is provided with an internal thread hole; The rear lug (37) is hinged to the rear mounting base (43) via a rear pin (38). The front end of the rear lug (37) is provided with an internal thread hole, and the internal thread direction of the rear lug (37) is opposite to that of the internal thread direction of the front lug (32). The threads at both ends of the double-ended stud are turned in opposite directions and engage with the internal threaded holes of the front lug (32) and the rear lug (37) respectively. The overall length of the tie rod assembly (3) can be adjusted by rotating the double-ended stud.

7. The adjustable throat area nozzle structure according to claim 6, characterized in that, The pull rod assembly (3) also includes a front nut (34) and a rear nut (36). The front nut (34) is screwed onto the double-ended stud and close to the front lug (32) to lock and prevent loosening. The rear nut (36) is screwed onto the double-ended stud and close to the rear lug (37) to lock and prevent loosening.

8. The adjustable throat area nozzle structure according to claim 1, characterized in that, A reinforcing ring (45) is provided at the outlet of the movable nozzle (4).

9. The adjustable throat area nozzle structure according to claim 4, characterized in that, A retaining ring (41) is provided at the front end of the straight section (42) of the moving nozzle.

10. The adjustable throat area nozzle structure according to claim 1, characterized in that, A fixed nozzle mounting edge (21) is provided at the front end of the fixed nozzle (2); The inner cone (5) includes, from front to back, an inner cone mounting edge (52), an inner cone front section (53), and an inner cone rear section (54); the inner cone front section (53) is cylindrical, and the inner cone rear section (54) is conical.

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