A double strut flame holder with trapezoidal grooves and trapezoidal tabs

Abstract

The present application relates to a kind of double-plate flame stabilizer with trapezoidal groove and trapezoidal block, double-plate flame stabilizer contains mirror image same upper support plate and lower support plate, upper support plate and lower support plate are composed of outer inclined surface, outer straight section, inner straight section, arc tail edge and nozzle, the inner straight section of upper support plate and lower support plate forms the inner side airflow passage of double-plate flame stabilizer, 3~5 trapezoidal grooves and trapezoidal blocks are alternately arranged at the tail end of the inner straight section of upper support plate and lower support plate.The advantages and beneficial effects obtained by the present application are that the double-plate flame stabilizer with trapezoidal groove and trapezoidal block is used in the hyperburning ramjet combustion chamber, which can carry more fuel, burn more stably, burn faster and have smaller total pressure loss.

Description

Technical Field

[0001] This invention relates to a double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions, which can be used in the combustion chamber of a scramjet engine and belongs to the field of aerospace technology. Background Technology

[0002] Scramjet engines, due to their superior performance at high Mach numbers, have gradually become the preferred propulsion system for hypersonic vehicles, attracting the attention of major aerospace powers. Because the residence time of the airflow within the scramjet combustor is extremely short, maximizing the conversion of the fuel's chemical energy into thermal energy within a limited space and time is one of the key technologies in scramjet combustor research. Scramjet combustors typically employ a stator flame stabilizer to create a recirculation zone, increasing fuel mixing and the residence and reaction time of the fuel-air mixture, thereby improving combustion efficiency and shortening the length of the combustion zone. The stator flame stabilizer configuration is a significant factor influencing the performance of the scramjet combustor.

[0003] In conventional flame stabilizers, the fuel jet is parallel to the supersonic incoming flow, resulting in relatively poor fuel distribution and mixing efficiency in space. This leads to a longer complete combustion distance and severely affects the expansion of combustion products. Stabilizers with staggered tail structures and tail wedge structures enhance fuel convection and diffusion by introducing large-scale flow vortices into the flow field. However, the recirculation zone of such stabilizers is significantly reduced, and the flow vortices can cause combustion instability, thus affecting the reaction process. At the same time, the total pressure loss of the combustion chamber also increases sharply, severely impacting the performance of the scramjet combustor. Summary of the Invention

[0004] The purpose of this invention is to provide a double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions. Trapezoidal grooves and trapezoidal protrusions are alternately arranged at the end of the straight section on the inner side of the upper plate and the inner side of the lower plate of the double-plate flame stabilizer. While bearing more fuel combustion, it is conducive to rapid ignition and more stable combustion, and effectively shortens the distance required for complete fuel combustion. Moreover, the total pressure loss is smaller than other plate solutions that achieve the same combustion performance.

[0005] The present invention is achieved through the following technical solution.

[0006] A double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions is provided. On the inner straight section tail end of the upper plate and the lower plate of the double-plate flame stabilizer, 3 to 5 trapezoidal grooves and 3 to 5 trapezoidal protrusions are alternately arranged. One trapezoidal groove is divided into two halves and arranged on both sides. The trapezoidal grooves on the inner side of the upper plate and the trapezoidal grooves on the inner side of the lower plate are mirror images of each other. The trapezoidal protrusions on the inner side of the upper plate and the trapezoidal protrusions on the inner side of the lower plate are also mirror images of each other.

[0007] Furthermore, the dual-support plate flame stabilizer has an extension determined by the specific engine, with a chord length of 30-50mm. It includes an upper support plate and a lower support plate that are mirror images of each other. The upper and lower support plates are mainly composed of an outer inclined surface, an outer straight section, an inner straight section, an arc-shaped trailing edge, and a nozzle. An inner airflow channel is formed between the inner straight sections of the upper and lower support plates, with a height of 3-7mm. The outer inclined surface and the inner straight section of the upper and lower support plates intersect at the leading edge with an angle of 10°-13°. The inner straight section has a chord length of 20-35mm in the support plate direction. The outer straight section is located behind the outer inclined surface and has a chord length of 3-15mm in the support plate direction. The arc-shaped trailing edge consists of a vertical surface and a rounded corner surface. The structure consists of an inclined surface and an arc-shaped tail edge forming a concave step on the inner side of the upper and lower support plates. The vertical surface of the arc-shaped tail edge connects with the tail edge of the inner straight section. The inclined surface of the arc-shaped tail edge and the outer straight section form a thin-walled tail structure with an included angle of 1°~5°. The thickness of the thin-walled tail structure at the tail edge is 0.25~2mm. The rounded corner of the arc-shaped tail edge provides a rounded transition between the vertical surface and the inclined surface, with a radius of 3~8mm. The distance between the outer straight section and the inner straight section (i.e., the height of the upper and lower support plates) is 5~10mm. A nozzle is arranged at the arc-shaped tail edge at the midpoint of the height of the upper and lower support plates, with a nozzle diameter of 0.5~2mm and a spacing of 2.5~6mm between adjacent nozzles.

[0008] Furthermore, the trapezoidal groove and trapezoidal protrusion are isosceles trapezoids in the top view. The tail edges of the trapezoidal groove and trapezoidal protrusion are flush with the tail edge of the inner straight section. The height of the trapezoid is 7.5~15mm, and the angle between the two sides of the trapezoid is 55°~75°. The trapezoidal groove is arranged in a positive direction with the front short side and the rear long side. The width of the front short side of the trapezoidal groove is 0.5~3mm, and the width of the rear long side of the trapezoidal groove is 12~17mm. The trapezoidal protrusion is arranged in a reverse direction with the front long side and the rear short side. The width of the front long side of the trapezoidal protrusion is 12~17mm, and the width of the rear short side of the trapezoidal protrusion is 0.5~3mm. The trapezoidal groove is a groove of equal depth, with a concave depth of 1~2mm relative to the inner straight section. The trapezoidal protrusion is a wedge-shaped protrusion. The front long side of the trapezoidal protrusion is located on the inner straight section, and the rear short side of the trapezoidal protrusion protrudes 0.8~1.5mm higher than the inner straight section.

[0009] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0010] First, it can hold more fuel. The double-plate flame stabilizer has an airflow channel between the upper and lower plates. After the trapezoidal grooves and trapezoidal protrusions are alternately arranged on the inner side of the double plates, a large-scale flow vortex with reverse rotation can be introduced in the wake region of the plates. This can enhance the thermal and mass convection between the main flow and the wake flow of the plates. Therefore, compared with the conventional single-plate flame stabilizer, it can hold about twice the amount of fuel for stable and efficient combustion.

[0011] Secondly, combustion is more stable. The double-plate flame stabilizer has a central airflow channel. After the trapezoidal grooves and trapezoidal protrusions are alternately arranged on the inner side of the double plates, a large-scale flow vortex rotating in the opposite direction can be introduced. The arc-shaped trailing edge configuration moves the fuel nozzle forward. Therefore, after the fuel is injected, it is quickly mixed in the low-speed zone formed by the arc-shaped trailing edge through the action of the flow vortex, which is conducive to rapid ignition and more stable combustion.

[0012] Third, it has a fast combustion speed. The double-support plate flame stabilizer has a central airflow channel, with trapezoidal grooves and trapezoidal protrusions arranged alternately on the inner side to introduce large-scale flow vortices. The arc-shaped trailing edge configuration moves the fuel nozzle forward. After the fuel is injected, it is rapidly mixed by the flow vortex in the low-speed zone of the arc-shaped trailing edge. The large-scale flow vortex can also enhance the thermal and mass convection between the mainstream and the trailing plate wake flow. Therefore, it can be rapidly ignited near the trailing plate and can burn efficiently downstream.

[0013] Fourth, the total pressure loss is small. To achieve the same stable and efficient combustion with the same amount of fuel, the total pressure loss is smaller when the trapezoidal grooves and trapezoidal protrusions are alternately arranged inside the double-plate flame stabilizer, compared to increasing the number of conventional single-plate flame stabilizers or increasing the thickness of the upper and lower plates of conventional double-plate flame stabilizers. Attached Figure Description

[0014] Figure 1 This is an isometric view of the double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions in this invention.

[0015] Figure 2 This is an isometric view of the lower support plate of the double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions in this invention.

[0016] Figure 3 This is a top view of the lower support plate of the double-support plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions in this invention.

[0017] Figure 4 This is a side view of the double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions in this invention.

[0018] Figure 5 This is a front view of the double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions in this invention.

[0019] Figure 6 This is a rear view of the double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions in this invention.

[0020] Figure 7 This is a streamline diagram of the double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions in this invention.

[0021] In the attached diagram, 1 is the upper support plate; 2 is the lower support plate; 3 is the outer inclined surface; 4 is the outer straight section; 5 is the inner straight section; 6 is the arc-shaped tail edge; 7 is the nozzle; 8 is the trapezoidal groove; 9 is the trapezoidal protrusion; 10 is the leading edge; and 11 is the inner airflow channel.

[0022] L1 is the span of the double-plate flame stabilizer; L2 is the chord length of the double-plate flame stabilizer; L3 is the chord length of the inner straight section in the support plate; L4 is the trapezoidal height of the trapezoidal groove and the trapezoidal protrusion; L5 is the width of the front short side of the trapezoidal groove; L6 is the width of the rear long side of the trapezoidal groove; L7 is the width of the front long side of the trapezoidal protrusion; L8 is the width of the rear short side of the trapezoidal protrusion; L9 is the spacing between adjacent nozzles; L10 is the chord length of the outer straight section in the support plate; α1 is the distance between the outer inclined surface and the inner straight section. Angle; α2 is the included angle between the two waists of the trapezoidal groove; α3 is the included angle between the two waists of the trapezoidal protrusion; α4 is the included angle of the thin-walled structure at the tail of the support plate; H1 is the depth of the trapezoidal groove relative to the inner straight section; H2 is the height of the rear short side of the trapezoidal protrusion relative to the inner straight section; H3 is the thickness of the thin-walled structure at the tail edge of the support plate; H4 is the distance between the outer straight section and the inner straight section; S1 is the height of the inner airflow channel; R1 is the radius of the rounded corner of the arc-shaped tail edge; D is the nozzle diameter. Detailed Implementation

[0023] The following will be combined with the appendix Figures 1-6 The present invention will be further described in detail with reference to the embodiments.

[0024] A double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions is provided. On the inner straight section 5 of the upper plate 1 and the lower plate 2, 3 to 5 trapezoidal grooves 8 and 3 to 5 trapezoidal protrusions 9 are alternately arranged. The trapezoidal grooves 8 on the inner side of the upper plate 1 and the trapezoidal grooves 8 on the inner side of the lower plate 2 are mirror images of each other. The trapezoidal protrusions 9 on the inner side of the upper plate 1 and the trapezoidal protrusions 9 on the inner side of the lower plate 2 are also mirror images of each other. In this embodiment, 3 trapezoidal grooves 8 and 3 trapezoidal protrusions 9 are alternately arranged, wherein one trapezoidal groove 8 is divided into two halves and arranged on both sides.

[0025] As a further improvement to this embodiment of the invention, the dual-support flame stabilizer has an extension L1 determined by the specific engine, specifically 50mm in this embodiment, and a chord length L2 of 30~50mm, specifically 32mm in this embodiment. It includes an upper support plate 1 and a lower support plate 2 that are mirror images of each other. The upper support plate 1 and the lower support plate 2 are mainly composed of an outer inclined surface 3, an outer straight section 4, an inner straight section 5, an arc-shaped trailing edge 6, and a nozzle 7. An inner airflow channel 11 is formed between the inner straight sections 5 of the upper support plate 1 and the lower support plate 2. The height S1 of the flow channel 11 is 3~7mm, specifically 4mm in this embodiment. The outer inclined surface 3 of the upper support plate 1 and the lower support plate 2 intersects the inner straight section 5 at the leading edge 10, with an included angle α1 of 10°~13°, specifically 11.7° in this embodiment. The chordal length L3 of the inner straight section 5 in the support plate is 20~35mm, specifically 24mm in this embodiment. The outer straight section 4 is located behind the outer inclined surface 3, and its chordal length L10 in the support plate is 3~15mm, specifically 6.54mm in this embodiment. The arc-shaped tail edge... 6 is composed of a vertical surface, a rounded corner surface, and an inclined surface. The curved tail edge 6 forms a concave step structure on the inner side of the upper support plate 1 and the lower support plate 2. The vertical surface of the curved tail edge 6 connects with the tail edge of the inner straight section 5. The inclined surface of the curved tail edge 6 forms a thin-walled tail structure with the outer straight section 4. The included angle α4 is 1°~5°, specifically 2.5° in this embodiment. The thickness H3 of the thin-walled tail structure at the tail edge is 0.25~2mm, specifically 0.3mm in this embodiment. The rounded corner surface of the curved tail edge 6 provides a rounded transition between the vertical surface and the inclined surface. The radius R1 of the rounded corner surface is 3~8mm, specifically 4mm in this embodiment. The distance between the outer straight section 4 and the inner straight section 5 (that is, the height H4 of the upper support plate 1 and the lower support plate 2) is 5~10mm, specifically 6.3725mm in this embodiment. The nozzle 7 is arranged at the arc edge opposite the middle position of the height of the upper support plate 1 and the lower support plate 2. The diameter D of the nozzle 7 is 0.5~2mm, specifically 1mm in this embodiment. The distance L9 between adjacent nozzles 7 is 2.5~6mm, specifically 3.173mm in this embodiment.

[0026] As a further improvement of this embodiment of the invention, the trapezoidal groove 8 and trapezoidal protrusion 9 are isosceles trapezoids in the top view. The trailing edges of the trapezoidal groove 8 and trapezoidal protrusion 9 are flush with the trailing edge of the inner straight section 5. The height L4 of the trapezoid is 7.5~15mm, specifically 10mm in this embodiment. The included angles α2 and α3 of the two sides of the trapezoid are equal, ranging from 55° to 75°, specifically 64.695° in this embodiment. The trapezoidal groove 8 is arranged in a positive direction with the front short side and the rear long side. The width L5 of the front short side of the trapezoidal groove 8 is 0.5mm~3mm, specifically 2mm in this embodiment. The width L6 of the rear long side of the trapezoidal groove 8 is 12~17mm, specifically 14mm in this embodiment. The trapezoidal protrusion 9 is arranged in a trapezoidal shape with the front long side and the rear short side in opposite directions. The width L7 of the front long side of the trapezoidal protrusion 9 is 12~17mm, specifically 14.667mm in this embodiment. The width L8 of the rear short side of the trapezoidal protrusion 9 is 0.5~3mm, specifically 2mm in this embodiment. The trapezoidal groove 8 is a groove of equal depth. The depth H1 of the groove relative to the inner straight section 5 is 1~2mm, specifically 1.35mm in this embodiment. The trapezoidal protrusion 9 is a wedge-shaped protrusion. The front long side of the trapezoidal protrusion 9 is located on the inner straight section 5. The height H2 of the rear short side of the trapezoidal protrusion 9 relative to the inner straight section 5 is 0.8~1.5mm, specifically 1.1mm in this embodiment.

[0027] The embodiments described above are merely preferred embodiments of the present invention and not an exhaustive list of all possible implementations of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A double-plate flame stabilizer with trapezoidal grooves and trapezoidal protrusions, characterized in that, On the inner straight section (5) of the upper support plate (1) and the lower support plate (2) of the double support plate flame stabilizer, 3 to 5 trapezoidal grooves (8) and 3 to 5 trapezoidal protrusions (9) are alternately arranged. One trapezoidal groove (8) is divided into two halves and arranged on both sides. The trapezoidal groove (8) on the inner side of the upper support plate (1) and the trapezoidal groove (8) on the inner side of the lower support plate (2) are mirror images. The trapezoidal protrusion (9) on the inner side of the upper support plate (1) and the trapezoidal protrusion (9) on the inner side of the lower support plate (2) are mirror images. The dual-support plate flame stabilizer has an extension determined by the specific engine, with a chord length of 30-50mm. It includes an upper support plate (1) and a lower support plate (2) that are mirror images of each other. The upper support plate (1) and the lower support plate (2) are mainly composed of an outer inclined surface (3), an outer straight section (4), an inner straight section (5), an arc-shaped trailing edge (6), and a nozzle (7). An inner airflow channel (11) is formed between the inner straight section (5) of the upper support plate (1) and the lower support plate (2). The inner airflow channel (11) is 3-7mm high. The outer inclined surface (3) of the upper support plate (1) and the inner straight section (5) intersect at the leading edge (10) with an angle of 10°-13°. The inner straight section (5) is 20-35mm long in the chord direction of the support plate. The outer straight section (4) is located behind the outer inclined surface (3). The outer straight section (4) is 3-50mm long in the chord direction of the support plate. 15mm, the arc-shaped tail edge (6) is composed of a vertical surface, a rounded surface and an inclined surface. The arc-shaped tail edge (6) forms an inwardly concave step structure on the inner side of the upper support plate (1) and the lower support plate (2). The vertical surface of the arc-shaped tail edge (6) is connected to the tail edge of the inner straight section (5). The inclined surface of the arc-shaped tail edge (6) and the outer straight section (4) form a tail thin-wall structure with an included angle of 1°~5°. The tail thin-wall structure is 0.25~2mm thick at the tail edge. The rounded surface of the arc-shaped tail edge (6) makes a rounded transition between the vertical surface and the inclined surface. The radius of the rounded surface is 3~8mm. The distance between the outer straight section (4) and the inner straight section (5) is 5~10mm. The nozzle (7) is arranged at the arc-shaped tail edge opposite the middle position of the height of the upper support plate (1) and the lower support plate (2). The nozzle (7) has a diameter of 0.5~2mm and the distance between adjacent nozzles (7) is 2.5~6mm. The trapezoidal groove (8) and trapezoidal protrusion (9) are isosceles trapezoids when viewed from above. The trailing edges of the trapezoidal groove (8) and trapezoidal protrusion (9) are flush with the trailing edge of the inner straight section (5). The height of the trapezoid is 7.5~15mm, and the angle between the two sides of the trapezoid is 55°~75°. The trapezoidal groove (8) is arranged in a positive direction with the front short side and the rear long side. The width of the front short side of the trapezoidal groove (8) is 0.5~3mm, and the width of the rear long side of the trapezoidal groove (8) is 12~17mm. The trapezoidal protrusion (9) is... The trapezoidal arrangement is in the opposite direction of the front long side and the rear short side. The front long side of the trapezoidal protrusion (9) is 12~17mm wide, and the rear short side of the trapezoidal protrusion (9) is 0.5~3mm wide. The trapezoidal groove (8) is a groove of equal depth, with a recessed depth of 1~2mm relative to the inner straight section (5). The trapezoidal protrusion (9) is a wedge-shaped protrusion. The front long side of the trapezoidal protrusion (9) is located on the inner straight section (5), and the rear short side of the trapezoidal protrusion (9) has a protrusion height of 0.8~1.5mm relative to the inner straight section (5).

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