Front switching section structure and fan-shaped combustion chamber test piece

Abstract

The invention provides a front switching section structure and a fan-shaped combustion chamber test piece, and relates to the technical field of aero-engine combustion chamber test structures. The front switching section structure comprises an air inlet circular pipe section, a rectifying pipe and a circular rotating fan pipe section. An inner channel in the air inlet circular pipe section forms a part of an air inlet channel, the circular rotating fan pipe section forms the other part of the air inlet channel, meanwhile, the circular rotating fan pipe section is provided with a first end and a second end which are oppositely arranged in the circulation direction of the air inlet channel, the cross section of the first end is circular, and the first end is fixedly connected with the air inlet circular pipe section. And the cross section of the second end is fan-shaped. The rectifying pipe is arranged in the gas inlet circular pipe section, the axis of the rectifying pipe is parallel to the axis of the gas inlet circular pipe section, gas in the gas inlet circular pipe section is rectified through the rectifying pipe, then the gas flow in the circular rotating fan pipe section is more stable, and the stability of the gas flow entering the combustion chamber from the front switching section structure can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine combustion chamber test structures, and more particularly, to a front transition section structure and a sector combustion chamber test piece. Background Art

[0002] The technology of aero-engine combustion chambers needs to carry out technical verification through single-head, multi-head to full-ring combustion chamber tests from paper design to application in core engine / overall engine tests. Single-head combustion chamber tests are generally used for screening multiple combustion chamber schemes, screening out one or several schemes with better comprehensive performance from multiple schemes, and then carrying out further test verification in sector combustion chambers and even full-ring combustion chambers. Since the equipment resource conditions required for full-ring combustion chambers are very high, high-temperature and high-pressure tests are generally carried out on sector combustion chambers.

[0003] Limited by domestic test resources, very few scientific research institutions are capable of carrying out high-temperature and high-pressure combustion tests. During the development of multi-head sector combustion chambers, there are situations where the design space for the length of the test piece is insufficient (limited by the test cell building), and the cross-sectional area of the test rig pipeline is much smaller than the cross-sectional area of the sector combustion chamber flow path. At this time, the inlet flow state of the sector combustion chamber is a short sudden expansion. The short sudden expansion flow state is prone to flow separation, making the inlet flow of the sector combustion chamber unstable, affecting the test results, and even causing safety problems of flow-pipeline coupling resonance under certain conditions. How to improve the inlet flow stability of the combustion chamber under the short sudden expansion flow state has become an urgent technical problem in this field. Summary of the Invention

[0004] A brief overview of one or more aspects is given below to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects, and is neither intended to identify key or decisive elements of all aspects nor to attempt to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that follows.

[0005] The purpose of the present invention is to provide a front transition section structure, which can solve the technical problem of poor inlet flow stability of the combustion chamber under the short sudden expansion flow state existing in the prior art.

[0006] The purpose of the present invention is also to provide a sector combustion chamber test piece, which can solve the technical problem of poor inlet flow stability of the combustion chamber under the short sudden expansion flow state existing in the prior art.

[0007] The embodiments of the present invention can be implemented in the following ways:

[0008] A front transition section structure, which is used to form an intake channel for gas flow; the front transition section structure includes:

[0009] An intake circular tube section, and the internal channel of the intake circular tube section serves as part of the intake channel;

[0010] A rectifying tube, which is arranged inside the intake circular tube section, and the axis of the rectifying tube is parallel to the axis of the intake circular tube section; a first flow channel is formed between the intake circular tube section and the rectifying tube, a second flow channel is formed inside the rectifying tube, and the internal channel of the intake circular tube section includes the first flow channel and the second flow channel; and

[0011] A circular rotating fan tube section, the internal channel of the circular rotating fan tube section serves as another part of the intake channel, and the circular rotating fan tube section has a first end and a second end arranged along the flow direction of the intake channel. The cross-section of the first end is circular, and the first end is fixedly connected to the intake circular tube section; the cross-section of the second end is fan-shaped.

[0012] Optionally, the fan shape has an inner arc section and an outer arc section opposite to each other, and the distribution direction of the inner arc section and the outer arc section is the height direction of the front transition section structure; the inner arc section is located below the outer arc section;

[0013] The rectifying tube includes an arc-shaped part and a flat part connected to each other along the circumference. The arc-shaped part and the flat part enclose the second flow channel, and the flat part is located below the arc-shaped part.

[0014] Optionally, the height of the midpoint of the inner arc section is the same as the height of the flat part.

[0015] Optionally, the height of the midpoint of the outer arc section is the same as the height of the highest point of the intake circular tube section.

[0016] Optionally, the distance between the midpoint of the inner arc section and the midpoint of the outer arc section is h5, the height of the rectifying tube is h4, and the distance between the highest point of the rectifying tube and the highest point of the intake circular tube section is h2, and h5 = h2 + h4.

[0017] Optionally, the central angle of the arc-shaped part is greater than 180°, and the arc-shaped part is coaxially arranged with the intake circular tube section.

[0018] Optionally, a first connection bracket and a second connection bracket are respectively arranged at two ends of the rectifying tube in the length direction; the first connection bracket is arranged along the height direction, and two ends along the height direction are respectively fixedly connected to the rectifying tube and the intake circular tube section; the second connection bracket is arranged along the height direction, and two ends along the height direction are respectively fixedly connected to the rectifying tube and the intake circular tube section.

[0019] Optionally, the length of the circular rotating fan tube section is L1, and 0.4m ≤ L1 ≤ 0.6m;

[0020] The length of the rectifying tube is L2, and 0.1m ≤ L2 ≤ 0.14m.

[0021] Optionally, the plane where the outflow end of the rectifying tube is located coincides with the plane where the outflow end of the intake circular tube section is located.

[0022] A sector combustion chamber test piece, and the sector combustion chamber test piece includes the above-mentioned front transition section structure.

[0023] The beneficial effects of the front transition section structure and the sector combustion chamber test piece provided by the embodiments of the present invention include:

[0024] The embodiments of the present invention provide a front transition section structure, which is used to form an intake passage for gas flow. The front transition section structure includes an intake circular tube section, a rectifying tube, and a circular rotating fan tube section. The internal passage in the intake circular tube section forms part of the intake passage, and the circular rotating fan tube section forms another part of the intake passage. At the same time, the circular rotating fan tube section has a first end and a second end oppositely arranged along the flow direction of the intake passage. The cross-section of the first end is circular, and the first end is fixedly connected to the intake circular tube section, and the cross-section of the second end is fan-shaped. The rectifying tube is arranged in the intake circular tube section, and the axis of the rectifying tube is parallel to the axis of the intake circular tube section. It divides the internal space of the intake circular tube section into a first flow passage located between the rectifying tube and the intake circular tube section and a second flow passage located inside the rectifying tube. The rectifying tube rectifies the gas in the intake circular tube section, thereby making the airflow in the circular rotating fan tube section more stable and improving the airflow stability entering the combustion chamber from the front transition section structure.

[0025] The embodiments of the present invention also provide a sector combustion chamber test piece. The sector combustion chamber test piece includes the above-mentioned front transition section structure, so it also has the beneficial effect of being able to improve the airflow stability entering the combustion chamber. Description of the Drawings

[0026] After reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings, the above features and advantages of the present invention can be better understood. In the drawings, the components are not necessarily drawn to scale, and components with similar related characteristics or features may have the same or similar reference numerals.

[0027] Figure 1 Shows a schematic structural diagram of a sector combustion chamber test piece provided according to one aspect of the present invention;

[0028] Figure 2 Shows a schematic structural diagram of the meridian plane of the front transition section structure provided according to one aspect of the present invention;

[0029] Figure 3 Shows Figure 2 A schematic structural diagram at A-A in;

[0030] Figure 4 Shows a working point position diagram at the front transition section structure provided according to one aspect of the present invention;

[0031] Figure 5 Shows a modeling diagram of an existing circular-to-sector flow channel;

[0032] Figure 6 Shows Figure 5 A streamline diagram of the shown shape;

[0033] Figure 7 Shows a modeling diagram of the front transition section structure provided according to one aspect of the present invention;

[0034] Figure 8 Shows Figure 7 A streamline diagram of the shown shape;

[0035] Figure 9 Shows a velocity distribution cloud diagram at the inlet of the test section of the existing structure;

[0036] Figure 10 Shows a velocity distribution cloud diagram at the inlet of the test section in the sector combustion chamber test piece provided according to one aspect of the present invention;

[0037] Figure 11 Shows a division diagram of dividing the inlet cross-section of the test section into 12 regions along the circumferential direction;

[0038] Figure 12 Shows a broken line diagram of the non-uniformity of each region of the inlet cross-section of the test section.

[0039] Reference numerals:

[0040] 10 - Sector combustion chamber test piece; 100 - Front transition section structure; 110 - Intake circular pipe section; 111 - First flow channel; 112 - Second flow channel; 120 - Rectifying pipe; 121 - Arc part; 122 - Flat part; 130 - First connection bracket; 131 - First connecting rod; 132 - Second connecting rod; 140 - Second connection bracket; 141 - Third connecting rod; 144 - Fourth connecting rod; 150 - Circular rotating fan pipe section; 151 - First end; 152 - Second end; 153 - Outer arc section; 154 - Inner arc section; 155 - First connection arc section; 156 - Second connection arc section; 211 - Front measurement section; 212 - Combustion test inlet test rake; 213 - Combustion test section; 214 - Flame tube assembly; 215 - Fuel nozzle; 216 - Ignition electrode; 217 - Rear measurement section; 218 - Combustion test outlet test rake; 219 - Rear transition section. Detailed implementation manners

[0041] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below in conjunction with the accompanying drawings and specific embodiments are merely exemplary and should not be construed as imposing any limitation on the protection scope of the present invention.

[0042] In the description of the present invention, it should be noted that if terms such as "upper", "lower", "inner", "outer", "vertical", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0043] At the same time, it should be noted that if terms such as "first", "second", etc. are only used for differential description and should not be construed as indicating or implying relative importance.

[0044] In the description of the present invention, it should also be noted that unless otherwise clearly specified or limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, an integral connection, or a detachable connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, or the communication inside two elements, etc. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Figure 1 It is a structural schematic diagram of the sector combustion chamber test piece 10 provided for this embodiment. Figure 2 It is a structural schematic diagram of the meridian plane of the front transition section structure 100 provided for this embodiment. Figure 3 For Figure 2Schematic diagram of the structure at A-A in [Chinese]. Please refer to Figures 1 - 3 , this embodiment provides a front transition section structure 100. At the same time, it also provides a sector combustion chamber test piece 10.

[0046] The sector combustion chamber test piece 10 includes a front transition section structure 100. At the same time, the sector combustion chamber test piece 10 also includes a front measurement section 211, a combustion test section 213, a rear measurement section 217, and a rear transition section 219. The front transition section structure 100, the front measurement section 211, the combustion test section 213, the rear measurement section 217, and the rear transition section 219 are connected in sequence to form a gas passage. Specifically, clean air enters the front measurement section 211 through the intake passage formed by the front transition section structure 100, and enters the combustion test section 213 through the front measurement section 211. In the combustion test section 213, it mixes and burns with fuel to form high-temperature gas. The high-temperature gas is discharged from the rear transition section 219 after passing through the rear measurement section 217. Optionally, adjacent two components can be connected by fasteners such as bolts to connect the above components to form a structure as Figure 1 shown.

[0047] It should be noted that in this embodiment, the combustion test section 213 and the front measurement section 211 are two independent parts, and these two parts are connected by fasteners such as bolts. It can be understood that in some other embodiments, according to the interface constraint problem of the design space, the front measurement section 211 and the combustion test section 213 can also be integrally designed, that is, the functions of the front measurement section 211 and the combustion test section 213 are simultaneously realized by the same component.

[0048] To meet the test requirements, on the front measurement section 211, a combustion test inlet test rake 212 is installed, and the clean air is measured by the combustion test inlet test rake 212 before the clean air enters the combustion test section 213. Correspondingly, on the rear measurement section 217, a combustion test outlet test rake 218 is also installed, and the high-temperature gas formed by the combustion test section 213 is measured by the combustion test outlet test rake 218.

[0049] For the technical verification object, on the combustion test section 213, a flame tube assembly 214, a fuel nozzle 215, and an ignition plug 216 are installed. Further, in order to ensure the representativeness of the combustion chamber components, at least four heads are assembled on the sector-shaped combustion test section 213, that is, at least four fuel nozzles 215 are evenly distributed along the circumferential direction of the combustion test section 213. The outlet of the front transition section structure 100 (i.e., the opening at the second end 152) is the same as the main flow channels of the front measurement section 211 and the combustion test section 213, and all have a sector shape. The specific structure of the sector shape will be described later.

[0050] The front transition section structure 100 is used to form an intake passage for gas flow, so that clean air passing through this intake passage enters the front measurement section 211. The front transition section structure 100 includes an intake circular tube section 110, a rectifying tube 120, and a circular rotating fan tube section 150. The internal passage in the intake circular tube section 110 forms part of the intake passage, and the circular rotating fan tube section 150 forms another part of the intake passage. At the same time, the circular rotating fan tube section 150 has a first end 151 and a second end 152 that are oppositely arranged along the flow direction of the intake passage. The cross-section of the first end 151 is circular, and the first end 151 is fixedly connected to the intake circular tube section 110. The cross-section of the second end 152 is fan-shaped. The rectifying tube 120 is arranged in the intake circular tube section 110. The axis of the rectifying tube 120 is parallel to the axis of the intake circular tube section 110. Through the rectifying tube 120, the internal space of the intake circular tube section 110 is divided into a first flow passage 111 located between the rectifying tube 120 and the intake circular tube section 110, and a second flow passage 112 located inside the rectifying tube 120. The gas in the intake circular tube section 110 is rectified through the rectifying tube 120, so that the air flow in the circular rotating fan tube section 150 is more stable, and thus the air flow stability entering the combustion chamber from the front transition section structure 100 can be improved.

[0051] Specifically, as Figure 2 and Figure 3 shown, in this embodiment, the intake circular tube section 110, the rectifying tube 120, and the circular rotating fan tube section are all tubular structures with a certain length (such as the dimension in the left-right direction shown in Figure 2 ). The circumferences of these tubular structures are closed, so as to enclose a passage for clean gas to flow inside. The rectifying tube 120 is arranged in the intake circular tube section 110, and its axis is parallel to the axis of the intake circular tube section 110. In this way, the flow direction of the second flow passage 112 enclosed by the rectifying tube 120 is the same as that of the first flow passage 111 between the intake circular tube section 110 and the rectifying tube 120. Both the intake circular tube section 110 and the circular rotating fan tube section 150 are load-bearing casings. At the same time, in order to ensure strength, the circular rotating fan tube section 150 needs to be designed with a streamlined transition shape from the first end 151 to the second end 152.

[0052] As Figure 3 shown, in this embodiment, the fan shape includes an inner arc section 154 and an outer arc section 153 that are oppositely arranged. The radius of the inner arc section 154 is smaller than that of the outer arc section 153. The distribution direction of the inner arc section 154 and the outer arc section 153 (i.e., Figure 3The vertical direction (in the up-down direction) is the height direction of the front transition section structure 100. The inner arc section 154 is located below the outer arc section 153. Correspondingly, the outer arc section 153 is located above the inner arc section 154, and the height of the outer arc section 153 is higher than that of the inner arc section 154. At the same time, the sector also includes a first connecting arc section 155 and a second connecting arc section 156 on both sides. The inner arc section 154 and the outer arc section 153 are smoothly connected through the first connecting arc section 155 and the second connecting arc section 156, so that a circumferentially closed sector is formed by connecting the head and tail of the inner arc section 154, the first connecting arc section 155, the outer arc section 153, and the second connecting arc section 156.

[0053] Specifically, in this embodiment, the inner arc section 154 and the outer arc section 153 are arc segments with the same center and different radii. At the same time, the central angles corresponding to the inner arc section 154 and the outer arc section 153 are the same, both being the θ angle as shown in Figure 3 shown.

[0054] The rectifier tube 120 includes an arc-shaped part 121 and a flat part 122 that are connected to each other along the circumference. The arc-shaped part 121 and the flat part 122 enclose a second flow channel 112, and the flat part 122 is located below the arc-shaped part 121. In other words, in the height direction, the distance between the flat part 122 and the inner arc section 154 is less than the distance between most of the arc-shaped part 121 and the inner section. The flat part 122 is a horizontal plate member arranged perpendicular to the height direction, that is, in this embodiment, the height of each part of the flat part 122 is the same.

[0055] Specifically, the cross-section of the rectifier tube 120 is a truncated circle, and its contour can be regarded as the shape obtained by cutting off a part of a complete circle by a straight line.

[0056] Furthermore, the central angle of the arc-shaped part 121 is greater than 180°, that is, the arc-shaped part 121 is a major arc, and the arc-shaped part 121 is coaxially arranged with the intake circular pipe section 110. In this way, the flat part 122 is located below the axis of the circular pipe section.

[0057] Furthermore, the height of the midpoint of the inner arc section 154 is the same as the height of the flat part 122. As shown in Figure 3 shown, the midpoint of the inner arc section 154 is the highest point of the inner arc section 154, and the projection of the flat part 122 on the plane where the second end 152 is located is tangent to the inner arc section 154.

[0058] Furthermore, the height of the midpoint of the outer arc section 153 is the same as the height of the highest point of the intake circular pipe section 110. As shown in Figure 3 shown, the midpoint of the outer arc section 153 is the highest point of the outer arc section 153. The projection of the intake circular pipe section 110 on the plane where the second end 152 is located is internally tangent to the outer arc section 153, and the tangent point of the two is the highest point of the outer arc section 153, and at the same time, it is also the highest point of the intake circular pipe section 110.

[0059] Further, in this embodiment, the distance between the midpoints of the inner arc segment 154 and the outer arc segment 153 is h5, the height of the rectifier tube 120 is h4, and the distance between the highest point of the rectifier tube 120 and the highest point of the intake circular tube section 110 is h2, and h5 = h2 + h4. Further, the maximum distance between the flat plate portion 122 and the intake circular tube section 110, that is, the distance between the flat plate portion 122 and the lowest point of the intake circular tube section 110 is h3, and h3 + h5 is the diameter D1 of the intake circular tube section 110, and the inlet flow cross-sectional area S1 corresponding to the intake circular tube section 110 = π(D1 / 2) 2 。

[0060] In this embodiment, the rectifier tube 120 is fixedly installed inside the intake circular tube section 110 through a connecting bracket. Optionally, a first connecting bracket 130 and a second connecting bracket 140 are respectively arranged at both ends in the length direction of the rectifier tube 120. The first connecting bracket 130 is arranged along the height direction, and both ends in the height direction are fixedly connected to the rectifier tube 120 and the intake circular tube section 110 respectively; the second connecting bracket 140 is arranged along the height direction, and both ends in the height direction are fixedly connected to the rectifying section and the intake circular tube section 110 respectively. Through the combined action of the first connecting bracket 130 and the second connecting bracket 140, the rectifier tube 120 is supported in the middle of the intake circular tube section 110.

[0061] Specifically, the first connecting bracket 130 includes a first connecting rod 131 and a second connecting rod 132 arranged on the upper and lower sides of the rectifier tube 120. The upper end of the first connecting rod 131 is fixedly connected to the highest point of the intake circular tube section 110, and the lower end of the first connecting rod 131 is fixedly connected to the highest point of the arc-shaped portion 121 in the rectifier tube 120; the upper end of the second connecting rod 132 is fixedly connected to the flat plate portion 122 of the rectifier tube 120, and the lower end of the second connecting rod 132 is fixedly connected to the lowest point of the intake circular tube section 110. The second connecting bracket 140 includes a third connecting rod 141 and a fourth connecting rod 142 arranged on the upper and lower sides of the rectifier tube 120. The upper end of the third connecting rod 141 is fixedly connected to the highest point of the intake circular tube section 110, and the lower end of the third connecting rod 141 is fixedly connected to the highest point of the arc-shaped portion 121 in the rectifier tube 120; the upper end of the fourth connecting rod 142 is fixedly connected to the flat plate portion 122 of the rectifier tube 120, and the lower end of the fourth connecting rod 142 is fixedly connected to the lowest point of the intake circular tube section 110. Optionally, the first connecting bracket 130 and the second connecting bracket 140 can be fixedly connected to the rectifier tube 120 and the intake circular tube section 110 by means of welding or integral molding.

[0062] In this embodiment, the length of the circular rotating fan pipe section 150 is L1, where 0.4 m ≤ L1 ≤ 0.6 m; the length of the rectifying pipe 120 is L2, where 0.1 m ≤ L2 ≤ 0.14 m. Optionally, the length L1 of the circular rotating fan pipe section 150 can be set to 0.4 m, 0.5 m, or 0.6 m according to requirements; the length L2 of the rectifying pipe 120 can be set to 0.1 m, 0.12 m, or 0.14 m according to requirements.

[0063] In this embodiment, the plane where the outflow end of the rectifying pipe 120 is located coincides with the plane where the outflow end of the intake circular pipe section 110 is located. The outflow end of the rectifying pipe 120 is the end of the rectifying pipe 120 close to the circular rotating fan pipe section 150. Correspondingly, the outflow end of the intake circular pipe section 110 is also the end of the intake circular pipe section 110 close to the circular rotating fan pipe section 150.

[0064] In order to verify the stability of the intake air flow by the front transition section structure 100 provided in this embodiment, as Figure 4 shows the working point position diagram at the front transition section structure 100 provided in this embodiment. It can be seen from Figure 4 that the working point at the front transition section structure 100 provided in this embodiment exceeds the stable working boundary.

[0065] Figure 5 shows the modeling diagram of the existing circular rotating fan flow channel, Figure 6 shows Figure 5 the streamline diagram of the shown modeling, Figure 7 shows the modeling diagram of the front transition section structure 100 provided in this embodiment, Figure 8 shows Figure 7 the streamline diagram of the shown modeling. Perform a flow field analysis on the front transition section structure 100 provided in this embodiment and the existing structure. As in Figure 6 the shown streamline diagram, a recirculation zone B is generated in the circular rotating fan flow channel. In comparison, Figure 8 the recirculation zone disappears in

[0066] Figure 9 shows the velocity distribution nephogram at the inlet of the combustion test section of the existing structure, Figure 10 shows the velocity distribution nephogram at the inlet of the combustion test section 213 of the fan-shaped combustion chamber test piece 10 provided in this embodiment. With reference to Figure 9 and Figure 10 , analyze the velocity distribution at the inlet of the combustion test section 213 of the fan-shaped combustion chamber test piece 10 provided in this embodiment and the inlet of the combustion test section of the existing structure. Compare Figure 9 and Figure 10It can be seen that the velocity distribution at the inlet of the existing structure in the combustion test section is relatively uneven, with a lower velocity in the right region of the contour map. The velocity distribution at the inlet of the combustion test section 213 in the sector-shaped combustion chamber test piece 10 provided in this embodiment is more uniform.

[0067] Figure 11 The division diagram shows that the inlet cross-section of the test section is divided into 12 regions along the circumferential direction. Specifically, the 12 regions are c1, c2, c3... c12. Figure 12 The broken line diagram shows the non-uniformity of each region of the inlet cross-section of the combustion test section 213, and Figure 12 the abscissa in it is the 12 regions corresponding to those in Figure 11 and the ordinate is the non-uniformity corresponding to that region. And in Figure 12 the solid line is used to indicate the structure provided in this embodiment, and the dashed line is used to indicate the existing structure. It can be seen from Figure 12 that the circumferential non-uniformity of the inlet cross-section of the combustion test section 213 in the sector-shaped combustion chamber test piece 10 provided in this embodiment is better than that of the existing structure.

[0068] For the front transition section structure 100 and the sector-shaped combustion chamber test piece 10 provided in the embodiments of the present invention, by arranging the special-shaped rectifying tube 120 in the intake circular tube section 110 of the front transition section structure, the air flow in the intake passage becomes more stable and uniform, thus ensuring the air flow stability at the inlet cross-section of the combustion test section 213, which helps to better control the combustion process, makes the test results more reliable, reduces the risk of coupled resonance between the unstable flow and the pipeline, and has a higher test safety.

[0069] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A front transition section structure, which is used to form an intake channel for gas flow; Characterized in that, The front transition section structure includes: An intake circular tube section, and the internal channel of the intake circular tube section serves as part of the intake channel; A rectifying tube, which is arranged in the intake circular tube section, and the axis of the rectifying tube is parallel to the axis of the intake circular tube section; a first flow channel is formed between the intake circular tube section and the rectifying tube, and a second flow channel is formed inside the rectifying tube. The internal channel of the intake circular tube section includes the first flow channel and the second flow channel; and A circular rotating fan tube section, the internal channel of the circular rotating fan tube section serves as another part of the intake channel, and the circular rotating fan tube section has a first end and a second end arranged along the flow direction of the intake channel. The cross-section of the first end is circular, and the first end is fixedly connected to the intake circular tube section; the cross-section of the second end is fan-shaped.

2. The front transition section structure according to claim 1, Characterized in that, The fan shape has an inner arc section and an outer arc section opposite to each other, and the distribution direction of the inner arc section and the outer arc section is the height direction of the front transition section structure; the inner arc section is located below the outer arc section; The rectifying tube includes an arc-shaped part and a flat part connected to each other along the circumference. The arc-shaped part and the flat part enclose the second flow channel, and the flat part is located below the arc-shaped part.

3. The front transition section structure according to claim 2, Characterized in that, The height of the midpoint of the inner arc section is the same as the height of the flat part.

4. The front transition section structure according to claim 2, Characterized in that, The height of the midpoint of the outer arc section is the same as the height of the highest point of the intake circular tube section.

5. The front transition section structure according to claim 2, Characterized in that, The distance between the midpoint of the inner arc section and the midpoint of the outer arc section is h5, the height of the rectifying tube is h4, and the distance between the highest point of the rectifying tube and the highest point of the intake circular tube section is h2, h5 = h2 + h4.

6. The front transition section structure according to claim 2, Characterized in that, The central angle of the arc-shaped part is greater than 180°, and the arc-shaped part is coaxially arranged with the intake circular tube section.

7. The front transition section structure according to claim 2, Characterized in that, First connection brackets and second connection brackets are respectively arranged at both ends of the rectifying tube in the length direction; the first connection bracket is arranged along the height direction, and is fixedly connected to the rectifying tube and the intake circular tube section at both ends along the height direction; the second connection bracket is arranged along the height direction, and is fixedly connected to the rectifying tube and the intake circular tube section at both ends along the height direction.

8. The front transition section structure according to claim 1, Characterized in that, The length of the circular rotating fan tube section is L1, 0.4m ≤ L1 ≤ 0.6m; The length of the rectifying tube is L2, 0.1m ≤ L2 ≤ 0.14m.

9. The front transition section structure according to claim 1, Characterized in that, The plane where the outflow end of the rectifier tube is located coincides with the plane where the outflow end of the intake circular tube section is located.

10. A sector combustion chamber test piece, characterized in that the sector combustion chamber test piece includes the front transition section structure according to any one of claims 1-9.

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